Active gas generator

Abstract

The object of the present invention is to provide an active gas generating device having a structure for ejecting high-quality active gas that does not contain impurities. In addition, the active gas generating device (100C) of the present invention is provided with a gas separation structure for separating the gas flow between the housing inner space (33) and the discharge space (6C) by means of a cooling plate (9), an electrode pressing member (8), and a high voltage applying electrode portion (1C). The active gas generating device (100C) further comprises an auxiliary metal electrode (12) provided on the upper surface of the electrode dielectric film (11) of the high voltage applying electrode portion (1C). The auxiliary metal electrode (12) is provided so as to overlap with a portion of the active gas flow path when viewed from above, and is set to a ground potential.

Description

Technical Field

[0001] The present invention relates to an active gas generating device which generates active gas by dielectric barrier discharge in a parallel plate manner and supplies the active gas to a subsequent processing space. Background Art

[0002] As an active gas generating device that generates active gas by dielectric barrier discharge of a parallel plate system, there is an active gas generating device disclosed in Patent Document 1, for example.

[0003] In the conventional active gas generating device disclosed in Patent Document 1, a processing space such as a processing chamber exists at the rear stage of the device.

[0004] Conventional active gas generating devices utilize dielectric barrier discharge to generate active gases such as nitrogen radicals from source gases such as nitrogen and eject the active gases into a processing space.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: International Publication No. 2019 / 229873 Summary of the Invention

[0008] Problems to be solved by the invention

[0009] Conventional active gas generation devices are structured so that gas is directed into the discharge space after passing through the exposed high-voltage power supply space, such as a metal electrode for applying high voltage, provided on the high-voltage side electrode. In this case, if components of the metal electrode evaporate due to high temperatures or abnormal discharge, these components can directly enter the discharge space, potentially causing particle or metal contamination in the semiconductor film formation process performed in the processing space.

[0010] That is, conventional active gas generating devices have a problem in that they may not be able to output high-quality active gas.

[0011] The present invention aims to solve the above-mentioned problems and provide an active gas generating device having a structure that can eject high-quality active gas free of impurities by focusing on the shape and mounting structure of the electrode component and its peripheral portion.

[0012] Means for solving problems

[0013] The active gas generating device of the present invention generates active gas by activating a raw material gas supplied to a discharge space, and is characterized by comprising: a first electrode-forming portion; and a second electrode-forming portion disposed below the first electrode-forming portion, wherein the first electrode-forming portion comprises a first electrode dielectric film and a first metal electrode formed on the upper surface of the first electrode dielectric film, and the second electrode-forming portion comprises a second electrode dielectric film and a second metal electrode formed on the lower surface of the second electrode dielectric film, wherein an AC voltage is applied to the first metal electrode and the second metal electrode is set to a ground potential. In a dielectric space where the first and second electrode dielectric films face each other, an active gas generating device is provided. The discharge space includes a region where the first and second metal electrodes overlap in a plan view. The second electrode dielectric film has a gas ejection hole for ejecting the active gas downward. A path from the discharge space to the gas ejection hole is defined as an active gas flow path. The active gas generating device further includes a base flange having a conductive structure and a concave cross-sectional structure, including a central bottom region and a peripheral protrusion provided along the periphery of the central bottom region and protruding in a height direction. The second electrode forming portion is provided so that the second metal electrode contacts the central bottom region. The active gas generating device further includes: a conductive structure having conductivity. The conductive structure is provided on the peripheral protrusion of the base flange and is located above the first electrode constituting part without contacting the first electrode constituting part; the insulating material is provided between the conductive structure and the first electrode constituting part, the upper surface of the insulating material is in contact with the lower surface of the conductive structure, and the lower surface is in contact with the upper surface of the first metal electrode; the electrode supporting member is provided on the lower surface of the conductive structure in a manner of supporting the first electrode constituting part from below; and the metal shell is provided on the peripheral protrusion of the base flange and has a shell inner space for accommodating the conductive structure, the base flange has: a gas supply port for receiving the raw material gas from the outside; a gas passage The active gas generating device further comprises a base flange having a gas discharge path and a gas discharge hole for supplying the raw material gas to the discharge space; and a base flange gas discharge hole for downwardly discharging the active gas discharged from the gas discharge hole. The base flange is given a ground potential. The conductive structure, the electrode support member, and the first electrode constituting portion form a gas separation structure for separating the flow of gas between the space inside the housing and the discharge space. The active gas generating device further comprises a third metal electrode provided on the upper surface of the first electrode dielectric film independently of the first metal electrode. The third metal electrode is provided so as to overlap with a portion of the active gas flow path when viewed from above and is set to a ground potential.

[0014] Effects of the Invention

[0015] The active gas generating device of the present invention, by having the above-described gas separation structure, can reliably prevent impurities generated in the space inside the casing from mixing into the discharge space.

[0016] As a result, the active gas generating device of the present invention can spray high-quality active gas containing no impurities without damaging the first and second electrode dielectric films.

[0017] Furthermore, the active gas generating device of the present invention includes the third metal electrode set to the ground potential, thereby being able to mitigate the electric field intensity in the active gas flow path.

[0018] As a result, the active gas generating device of the present invention can intentionally reduce the electric field intensity in the processing space provided below the susceptor flange gas ejection hole without changing the structures of the gas ejection hole and the susceptor flange gas ejection hole.

[0019] Furthermore, the active gas generating device of the present invention, by having the aforementioned gas separation structure, reduces the need to improve the adhesion between the first and third metal electrodes and the upper surface of the first electrode dielectric film. Consequently, bulk metal, which is relatively easy to manufacture, can be used as the first and third metal electrodes, thereby simplifying the manufacturing process.

[0020] The objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is an explanatory diagram showing the overall structure of the active gas generating device according to the first embodiment of the present invention.

[0022] Figure 2 Yes Figure 1 A plan view of the upper surface structure of the high voltage applying electrode portion shown.

[0023] Figure 3 It is a cross-sectional view showing the cross-sectional structure of the high voltage applying electrode portion.

[0024] Figure 4 Yes Figure 1 A plan view of the lower surface structure of the ground potential electrode portion shown.

[0025] Figure 5 It is a cross-sectional view showing the cross-sectional structure of the ground potential electrode portion.

[0026] Figure 6 Yes Figure 1 A plan view of the flat configuration of the base flange is shown.

[0027] Figure 7It is a cross-sectional view showing the cross-sectional structure of the base flange.

[0028] Figure 8 It is a perspective view showing details of the gas buffer zone and the gas diffusion path.

[0029] Figure 9 Yes Figure 1 A plan view of the planar configuration of the insulation panel is shown.

[0030] Figure 10 It is a cross-sectional view showing the cross-sectional structure of an insulating plate.

[0031] Figure 11 Yes Figure 1 A plan view of the planar structure of the electrode pressing component shown.

[0032] Figure 12 It is a cross-sectional view showing the cross-sectional structure of the electrode pressing member.

[0033] Figure 13 Yes Figure 1 A plan view of the planar configuration of the cooling plate is shown.

[0034] Figure 14 It is a cross-sectional view showing the cross-sectional structure of the cooling plate.

[0035] Figure 15 This is a plan view showing the planar structure of the base flange of the second embodiment.

[0036] Figure 16 This is a cross-sectional view showing the cross-sectional structure of the base flange according to the second embodiment.

[0037] Figure 17 This is an explanatory diagram schematically showing the characteristics of the formation direction of the gas diffusion path.

[0038] Figure 18 It is an explanatory diagram showing the overall structure of the active gas generating device according to the third embodiment.

[0039] Figure 19 Yes Figure 18 A plan view of the upper surface structure of the high voltage applying electrode portion and the auxiliary metal electrode is shown.

[0040] Figure 20 It is a cross-sectional view showing the cross-sectional structure of the high voltage applying electrode portion and the auxiliary metal electrode.

[0041] Figure 21 Yes Figure 18 A plan view of the lower surface structure of the ground potential electrode portion shown.

[0042] Figure 22It is a cross-sectional view showing the cross-sectional structure of the ground potential electrode portion.

[0043] Figure 23 Yes Figure 18 A plan view of the planar configuration of the insulation panel is shown.

[0044] Figure 24 It is a cross-sectional view showing the cross-sectional structure of an insulating plate.

[0045] Figure 25 It is an explanatory diagram showing the overall structure of the active gas generating device according to the fourth embodiment.

[0046] Figure 26 Yes Figure 25 A plan view of the upper surface structure of the high voltage applying electrode portion and the auxiliary metal electrode is shown.

[0047] Figure 27 It is a cross-sectional view showing the cross-sectional structure of the high voltage applying electrode portion and the auxiliary metal electrode.

[0048] Figure 28 Yes Figure 25 A plan view of the lower surface structure of the ground potential electrode portion shown.

[0049] Figure 29 It is a cross-sectional view showing the cross-sectional structure of the ground potential electrode portion.

[0050] Figure 30 It is a cross-sectional view showing the overall structure of a first comparative active gas generating device.

[0051] Figure 31 It is a cross-sectional view showing the overall structure of a second comparative active gas generating device. DETAILED DESCRIPTION

[0052] <Implementation Method 1>

[0053] (Overall composition)

[0054] Figure 1 It is an explanatory diagram showing the overall structure of the active gas generating device according to the first embodiment of the present invention. Figure 1 The XYZ orthogonal coordinate system is described in . The active gas generating device 100 of the first embodiment generates active gas 52 (nitrogen radicals, etc.) obtained by activating the raw material gas 5 (nitrogen gas, etc.) supplied to the discharge space 6 .

[0055] The active gas generating device 100 includes, as main components, a metal case 3 , a base flange 4 , a high voltage applying electrode unit 1 , a ground potential electrode unit 2 , an insulating plate 7 , an electrode pressing member 8 , and a cooling plate 9 .

[0056] The base flange 4 has a concave cross-section and includes a central bottom region 48 and a peripheral protrusion 46 extending along the periphery of the central bottom region 48 and protruding in the height direction (+Z direction).

[0057] The metal case 3 is a metal case having an opening at the bottom. The metal case 3 mainly includes a case inner space 33 for accommodating the cooling plate 9 .

[0058] The metal housing 3 is fixed to the base flange 4, with the metal base flange 4 serving as its bottom surface. Specifically, the metal housing 3 is fixed to the peripheral protrusion 46 of the base flange 4. Therefore, the opening of the metal housing 3 is shielded by the base flange 4, and the metal housing 3 and the base flange 4 form a shielded space encompassing the housing interior space 33. Furthermore, the metal housing 3 is set to ground potential via the base flange 4.

[0059] A cooling plate 9 is disposed on the bottom portion of the housing interior space 33 in the active gas generating device 100. Specifically, the cooling plate 9 is disposed on the upper surface of the peripheral protrusion 46 of the base flange 4 so that the peripheral end of the cooling plate 9 contacts the upper surface of the peripheral protrusion 46 of the base flange 4. The cooling plate 9 is a conductive structure made of metal, such as a metal plate, and is disposed so as not to contact the metal housing 3.

[0060] On the other hand, the ground potential electrode portion 2, serving as a second electrode component, is disposed on the central bottom region 48 of the base flange 4. The ground potential electrode portion 2 primarily comprises an electrode dielectric film 21, serving as a second electrode dielectric film, and a metal electrode 20, serving as a second metal electrode, formed on the lower surface of the electrode dielectric film 21. Therefore, the ground potential electrode portion 2 is placed on the central bottom region 48 such that the metal electrode 20 contacts the central bottom region 48.

[0061] The combination of the high voltage applying electrode section 1 as the first electrode component and the ground potential electrode section 2 as the second electrode component constitutes an electrode pair having a discharge space 6 therein. The ground potential electrode section 2 is provided below the high voltage applying electrode section 1 .

[0062] The high voltage applying electrode unit 1 includes, as main components, an electrode dielectric film 11 as a first electrode dielectric film and a metal electrode 10 as a first metal electrode formed on the upper surface of the electrode dielectric film 11 .

[0063] An AC voltage is applied between the metal electrode 10 and the metal electrode 20 from the high frequency power supply 50 . Specifically, the AC voltage is applied to the metal electrode 10 from the high frequency power supply 50 , and the metal electrode 20 is set to a ground potential via the base flange 4 .

[0064] A discharge space 6 is provided in a closed space that is a dielectric space where the electrode dielectric film 11 and the electrode dielectric film 21 face each other, including a region where the metal electrodes 10 and 20 overlap in a plan view.

[0065] The electrode dielectric film 21 has gas ejection holes 23 for ejecting the active gas 52 into the lower (latter stage) processing space 63 through the gas ejection holes 43 of the susceptor flange 4 .

[0066] A gas ejection hole 43 (base flange gas ejection hole) is provided in the central portion of the central bottom region 48 of the base flange 4 at a position corresponding to the gas ejection hole 23 of the electrode dielectric film 21 without interposing the metal electrode 20 .

[0067] As described above, the cooling plate 9 is fixed to the peripheral protrusion 46 of the base flange 4. The insulating plate 7 is provided on the lower surface of the cooling plate 9. The high voltage applying electrode unit 1 is arranged so that the upper surface of the metal electrode 10 contacts the lower surface of the insulating plate 7.

[0068] An electrode pressing member 8, serving as an electrode support member, is provided on the lower surface of the cooling plate 9. The electrode pressing member 8 is provided in the outer peripheral region of the insulating plate 7 and the high-voltage applying electrode unit 1. Hereinafter, the combined structure of the insulating plate 7 and the high-voltage applying electrode unit 1 may be referred to simply as the "upper electrode assembly."

[0069] The electrode pressing member 8 has a pressing protrusion 8a with a portion of its lower portion protruding inward (in the direction of formation of the upper electrode group). The pressing protrusion 8a is provided so as to protrude inward in the horizontal direction (XY plane) so that its upper surface contacts the lower surface of the electrode dielectric film 11.

[0070] The upper electrode group is fixed to the lower surface of the cooling plate 9 by being sandwiched between the pressing protrusions 8 a of the electrode pressing member 8 and the cooling plate 9 .

[0071] Therefore, the electrode pressing member 8 functions as an electrode supporting member provided on the lower surface of the cooling plate 9 so as to support the high-voltage applying electrode unit 1 from below.

[0072] The electrode pressing member 8 is attached to the cooling plate 9 using stainless steel bolts. However, if these bolts are exposed to the flow 51 of the raw gas 5 in the gas relay region R4 described later, there is a risk of contamination from the stainless steel. Therefore, all bolts are attached from the housing interior space 33 side through the cooling plate 9 toward the electrode pressing member 8. The bolts are not shown in the figure. In this manner, the electrode pressing member 8 is attached to the lower surface of the cooling plate 9, sandwiching the upper electrode assembly between the pressing protrusion 8a and the cooling plate 9.

[0073] The plate-shaped insulating plate 7 as an insulating material is provided between the cooling plate 9 and the high voltage applying electrode unit 1 , with its upper surface in contact with the lower surface of the cooling plate 9 and its lower surface in contact with the upper surface of the metal electrode 10 of the high voltage applying electrode unit 1 .

[0074] Therefore, the cooling plate 9 is not in contact with the high-voltage applying electrode unit 1 via the insulating plate 7 , and is located above the high-voltage applying electrode unit 1 .

[0075] As described above, the active gas generating device 100 has a mounting feature in that the high voltage applying electrode portion 1 is not placed on the ground potential electrode portion 2 via a spacer, but is mounted on the cooling plate 9 above.

[0076] The active gas generating device 100 has the above-described mounting features, so that the height direction positioning of the cooling plate 9 can be determined solely by its contact surface with the peripheral protrusion 46 of the base flange 4. In other words, the height direction positioning of the cooling plate 9 can be determined solely by the height of the upper surface of the peripheral protrusion 46 of the base flange 4.

[0077] Therefore, the active gas generating device 100 can completely prevent gas leakage between the cooling plate 9 and the base flange 4 and cooling water leakage by accurately setting the formation position of the cooling plate 9 .

[0078] The base flange 4 has a gas supply port 34 on one side surface of the peripheral protrusion 46 and a gas passage 35 therein. The source gas 5 supplied from the outside flows from the gas supply port 34 along the gas passage 35 .

[0079] Furthermore, the base flange 4 has a gas relay region R4 above the central bottom region 48 (and mainly below the electrode pressing member 8 ) serving as a relay region for the raw material gas 5 between the gas passage 35 and the discharge space 6 .

[0080] Therefore, the raw material gas 5 flowing through the gas passage 35 is eventually supplied to the discharge space 6 via the gas relay region R4. Specifically, a gas buffer region 41 and a gas diffusion path 42 described below exist between the gas passage 35 and the gas relay region R4.

[0081] As described above, the base flange 4 includes the gas supply port 34 for receiving the raw material gas 5 from the outside and the gas passage 35 for supplying the raw material gas 5 to the discharge space 6 .

[0082] The gas relay region R4 is completely separated from the housing internal space 33 by the high voltage applying electrode unit 1 (first electrode component), the insulating plate 7 (insulating material), the electrode pressing member 8 , and the cooling plate 9 .

[0083] In order to achieve the above-mentioned complete separation, the contact surfaces between the cooling plate 9 and the base flange 4, the contact surfaces between the cooling plate 9 and the electrode pressing component 8, and the contact surfaces between the electrode pressing component 8 and the high voltage application electrode part 1 are respectively sealed based on O-rings (the O-rings are not shown in the figure).

[0084] Therefore, the flow of gas between the housing inner space 33 and the discharge space 6 is separated by at least the electrode pressing member 8 , the cooling plate 9 , and the high-voltage applying electrode unit 1 .

[0085] That is, the raw material gas 5 flowing in the gas relay region R4 does not mix into the housing inner space 33 , and conversely, impurities and the like present in the housing inner space 33 do not mix into the discharge space 6 via the gas relay region R4 .

[0086] The base flange 4 has a cooling water supply port 44 on the other side of the peripheral protrusion 46 . Cooling water as a cooling medium supplied from the outside flows through the peripheral protrusion 46 and is supplied to the cooling plate 9 from the cooling water passage port 451 .

[0087] The cooling plate 9 has a cooling water path 90 inside, which serves as a cooling medium path for cooling water supplied through the cooling water passage port 451. Therefore, the cooling plate 9 has a cooling function of cooling the high-voltage applying electrode unit 1 (electrode dielectric film 11) via the insulating plate 7 by flowing cooling water through the cooling water path 90.

[0088] Thus, the base flange 4 includes the cooling water supply port 44 for receiving cooling water as a cooling medium and the cooling water passage port 451 for supplying cooling water to the cooling plate 9 .

[0089] Hereinafter, a brief description will be given of the steps for installing the active gas generating device 100 having the above-described structure.

[0090] (1) The cooling plate 9 is turned over so that the relationship between the upper surface and the lower surface of the cooling plate 9 is reversed.

[0091] (2) The insulating plate 7 is placed on the lower surface of the cooling plate 9 .

[0092] (3) The high-voltage applying electrode unit 1 is placed on the insulating plate 7 in this order, followed by the metal electrode 10 and the electrode dielectric film 11 .

[0093] (4) The electrode pressing member 8 is placed on the lower surface of the cooling plate 9, and bolts are tightened between the cooling plate 9 and the electrode pressing member 8. As a result, the upper electrode assembly is attached to the lower surface of the cooling plate 9. At this point, the space between the cooling plate 9 and the electrode pressing member 8, and between the high-voltage applying electrode unit 1 and the electrode pressing member 8, is sealed.

[0094] (5) The ground potential electrode portion 2 is placed on the central bottom surface region 48 of the base flange 4 .

[0095] (6) The cooling plates 9 to which the upper electrode group is attached are returned to their original vertical relationship.

[0096] (7) The cooling plate 9 is placed on the peripheral protrusion 46 of the base flange 4, and bolts are fastened between the cooling plate 9 and the base flange 4. At this time, the cooling plate 9 and the base flange 4 are sealed.

[0097] In this manner, the active gas generating device 100 of the first embodiment can be assembled through the assembly steps (1) to (7).

[0098] In the active gas generating device 100 assembled as described above, the raw material gas 5 is supplied into the susceptor flange 4 from the gas supply port 34 provided on one side surface of the peripheral protrusion 46 of the susceptor flange 4 .

[0099] Within the peripheral protrusion 46 of the base flange 4, a flow 51 of the raw material gas 5 flows from the gas passage 35 through the gas buffer zone 41 and the gas diffusion path 42 (described later) toward the gas relay region R4. The gas flow 51 then flows from the gas relay region R4 toward the discharge space 6 between the high-voltage application electrode 1 and the ground potential electrode 2. Passing the raw material gas 5 through the discharge space 6, to which discharge power is applied, activates the raw material gas 5, producing an active gas 52. The active gas 52 is supplied to the processing space 63 below through the gas ejection holes 23 and the gas ejection holes 43. The path from the discharge space 6 to the gas ejection holes 23 is defined as the active gas flow path.

[0100] At this time, the housing inner space 33 can be set to a pressure from the atmospheric pressure of about 100 kPa to 1×10 －1 Pa~1×10 －3 The wide pressure range up to a high vacuum of about Pa. In particular, when the housing inner space 33 is brought to a high vacuum, even if a very small leak occurs between the housing inner space 33 and the discharge space 6, all of it will leak into the housing inner space 33, thus having the advantage of not affecting the object to be processed.

[0101] The active gas generating device 100 of the first embodiment is characterized in that it has a gas separation structure that separates the flow of gas between the housing inner space 33 and the discharge space 6 by the cooling plate 9 , the insulating plate 7 , the electrode pressing member 8 , and the high voltage applying electrode unit 1 .

[0102] Furthermore, separation of the flow of gas between the housing inner space 33 and the discharge space 6 can be achieved by providing at least the cooling plate 9 , the electrode pressing member 8 , and the high-voltage applying electrode unit 1 .

[0103] The active gas generating device 100 of the first embodiment includes the above-described gas separation structure, and can reliably prevent impurities generated in the housing inner space 33 from entering the discharge space 6 .

[0104] As a result, the active gas generating device 100 according to the first embodiment can spray high-quality active gas 52 containing no impurities without damaging the electrode dielectric films 11 and 21 .

[0105] Furthermore, the high-voltage applying electrode unit 1 can be cooled via the insulating plate 7 (insulating material) by the cooling function of the cooling plate 9 having the cooling water path 90 serving as a cooling medium path. Therefore, the temperature difference between regions within the dielectric film 11 (first electrode dielectric film) having the lower surface forming the discharge space 6 can be minimized.

[0106] The following describes the temperature difference between regions within the dielectric film. Thermal expansion caused by the discharge phenomenon in the discharge space 6 determines the upper limit of the power density. The electrode dielectric film 11 of the high-voltage application electrode unit 1 generates a temperature difference between the discharge region (the region where the metal electrode 10 is formed) that overlaps with the discharge space 6 when viewed from above, and the non-discharge region outside of it. This temperature difference within the electrode dielectric film 11 constitutes the temperature difference between regions within the dielectric film.

[0107] If the temperature difference between regions within the dielectric film increases, cracks may form due to thermal expansion, increasing the risk of damage to the electrode dielectric film 11. Therefore, if the temperature difference between regions within the dielectric film can be minimized by cooling the electrode dielectric film 11 via the insulating plate 7 and the metal electrode 10 using the cooling plate 9, a higher discharge power can be applied.

[0108] Therefore, the active gas generating device 100 of the first embodiment suppresses the temperature difference between the regions in the dielectric film, thereby increasing the discharge power applied to the discharge space 6 and thereby increasing the amount of active gas 52 generated.

[0109] Furthermore, by providing the insulating plate 7 between the cooling plate 9 and the metal electrode 10 , a short circuit phenomenon in which the metal electrode 10 and the cooling plate 9 are electrically connected can be reliably avoided.

[0110] The above effects are described below. A high potential is applied to the metal electrode 10 of the high voltage applying electrode unit 1 from a high frequency power supply 50, and the cooling plate 9 is grounded via the base flange 4. Therefore, a short circuit caused by direct contact between the cooling plate 9 and the metal electrode 10 must be avoided.

[0111] Therefore, the short circuit phenomenon between the metal electrode 10 of the high voltage applying electrode unit 1 and the cooling plate 9 is reliably prevented by the insulating plate 7 formed of an insulating material.

[0112] (High voltage applying electrode section 1)

[0113] Figure 2 Yes Figure 1 The plan view of the upper surface structure of the high voltage applying electrode unit 1 is shown in FIG. Figure 3 It is a cross-sectional view showing the cross-sectional structure of the high-voltage applying electrode unit 1 . Figure 2 The A-A section is Figure 3 . Figure 2 as well as Figure 3 The XYZ orthogonal coordinate systems are recorded respectively.

[0114] like Figures 1 to 3 As shown, the electrode dielectric film 11 of the high-voltage applying electrode unit 1 has a circular shape in a plan view.

[0115] The metal electrode 10 is provided on the upper surface of the electrode dielectric film 11 and is formed in an annular shape having a circular opening 15 at the center.

[0116] (Ground potential electrode portion 2)

[0117] Figure 4 Yes Figure 1 The plan view of the lower surface structure of the ground potential electrode portion 2 is shown. Figure 5 1 is a cross-sectional view showing the cross-sectional structure of the ground potential electrode portion 2 . Figure 4 The B-B section is Figure 5 . Figure 4 as well as Figure 5 The XYZ orthogonal coordinate systems are recorded respectively.

[0118] like Figure 1 、 Figure 4 as well as Figure 5 As shown, the electrode dielectric film 21 of the ground potential electrode portion 2 has a circular shape in a plan view.

[0119] The metal electrode 20 is provided on the lower surface of the electrode dielectric film 21 and is formed in an annular shape having a circular opening 25 at the center.

[0120] The metal electrode 20 is formed so as to encompass the entire metal electrode 10 in a plan view. Therefore, the discharge space 6 where the metal electrode 20 and the metal electrode 10 overlap in a plan view is substantially defined by the region where the metal electrode 10 is formed. Therefore, like the metal electrode 10, the discharge space 6 is formed in a circular ring shape with the gas ejection hole 23 as the center in a plan view.

[0121] The ground potential electrode portion 2 has a gas ejection hole 23 at the center thereof for ejecting downward the active gas 52 generated in the discharge space 6. The gas ejection hole 23 is formed to penetrate the electrode dielectric film 21.

[0122] like Figure 4 As shown, the gas ejection hole 23 does not overlap with the metal electrode 20 in a plan view, but is provided at the center of the opening 25 of the metal electrode 20 .

[0123] Furthermore, by setting the diameter of the gas ejection hole 23 to be sufficiently small, the gas ejection hole 23 can have a throttling function. In this specification, the term "throttling function" refers to a function that reduces the pressure in the area before and after the gas passes through the gas passage portion (gas ejection hole 23) relative to the pressure in the area before and after the gas passes through.

[0124] Specifically, when the length φ of the diameter of the gas ejection hole 23 is set to 0.69 mm, the formation depth is set to 1 mm, and the gas flow rate of the raw gas 5 is set to 1 slm, the pressure on the downstream side of the gas ejection hole 23 is 266 Pa (absolute pressure), and the pressure upstream (discharge space 6) can be set to about 30 kPa.

[0125] Thus, the gas ejection holes 23 having a throttling function are formed in the ground potential electrode portion 2. Therefore, a pressure difference is generated in the discharge space 6 downstream and upstream of the active gas generator 100, and the pressure in the discharge space 6 is maintained at approximately 10 kPa to 30 kPa.

[0126] (Base flange 4)

[0127] Figure 6 Yes Figure 1 A plan view of the planar configuration of the base flange 4 is shown, Figure 7 It is a cross-sectional view showing the cross-sectional structure of the base flange 4 . Figure 8 4 is a perspective view showing details of the gas buffer zone 41 and the gas diffusion path 42 described later. Figure 6 The C-C cross section is Figure 7 . Figures 6 to 8 The XYZ orthogonal coordinate systems are recorded respectively.

[0128] The base flange 4, which is made of metal and has electrical conductivity, is given a ground potential. Figure 1 、 Figures 6 to 8 As shown, the base flange 4 is circular in plan view and concave in cross-section. The base flange 4 has a central bottom region 48 that is circular in plan view and a peripheral protrusion 46 that is annular in plan view and extends upward (in the +Z direction) along the periphery of the central bottom region 48.

[0129] The base flange 4 has a gas ejection hole 43 (a gas ejection hole for the base flange) at the center position of the central bottom surface region 48 . The gas ejection hole 43 penetrates the base flange 4 .

[0130] The gas ejection holes 43 of the base flange 4 correspond to the gas ejection holes 23 and are formed on the upper surface at positions that coincide with the gas ejection holes 23 in a plan view.

[0131] By setting the diameter of the gas ejection hole 43 to be sufficiently small, the gas ejection hole 43 can have a throttling function. In this case, the "throttling function" refers to the function of reducing the pressure in the area before and after the gas ejection hole 43, which serves as the gas passage, compared to the pressure in the area before and after the gas ejection hole 43.

[0132] However, the active gas 52 generated in the discharge space 6 has a longer life when the pressure is low. Therefore, it is preferable that the gas ejection holes 23 closer to the discharge space 6 have a throttling function compared to the gas ejection holes 43 .

[0133] A central bottom surface area 48 and a peripheral protrusion 46 are provided from the center position to the periphery of the base flange 4 . A plurality of gas diffusion paths 42 and a gas buffer zone 41 are provided in the inner peripheral area of ​​the peripheral protrusion 46 .

[0134] The gas buffer zone 41, which is a gas internal flow path, is connected to the gas passage 35 and is formed in a ring shape in a plan view so as to surround the gas relay region R4. Figure 7 as well as Figure 8 As shown, the gas buffer area 41 has a groove structure in which grooves are formed when viewed in cross section, and thus can temporarily accommodate the raw material gas 5 .

[0135] A plurality of gas diffusion paths 42 are discretely provided between the gas buffer zone 41 and the gas relay region R4 , forming an internal gas flow path.

[0136] like Figure 6 As shown, the plurality of gas diffusion paths 42 are discretely provided at equal intervals along the formation direction (circumferential direction) of the gas buffer zone 41 .

[0137] By setting the width and depth of each gas diffusion path 42 sufficiently small, the gas diffusion paths 42 can have a throttling function. In this case, the "throttling function" refers to the function of reducing the pressure of the gas relay region R4 after the gas diffusion path 42 passes through the gas compared to the pressure of the gas buffer region 41 before the gas diffusion path passes through the gas diffusion path 42.

[0138] Specifically, the following usage example can be considered: the width of each gas diffusion path 42 is set to 1 mm, the height is set to 0.4 mm, and the formation length (depth length) is set to 3.6 mm relative to the gas travel direction. For a total of 24 gas diffusion paths 42 each having the above-mentioned structure, the gas flow rate of the raw gas 5 is set to 1 slm.

[0139] In this usage example, while the pressure on the downstream side of the gas diffusion path 42 is 30 kPa (absolute pressure), the pressure in the gas buffer zone 41 upstream thereof can be increased to 70 Pa or more.

[0140] The source gas 5 supplied into the susceptor flange 4 needs to flow uniformly throughout the entire 360° periphery toward the discharge space 6. This is because if the source gas 5 flows unevenly into the discharge space 6, a pressure difference proportional to the gas flow will occur in the discharge space 6, resulting in uneven discharge and reduced efficiency in generating the active gas 52.

[0141] like Figure 7 As shown, in the base flange 4, the raw material gas 5 supplied from the gas supply port 34 passes through the gas passage 35. The raw material gas 5 can be temporarily retained in the entire circumference of the gas buffer zone 41, which is a circular groove in a plan view.

[0142] The raw material gas 5, which has temporarily stagnated in the gas buffer zone 41, then flows toward the center through the plurality of gas diffusion paths 42. At this time, because each of the plurality of gas diffusion paths 42 has a throttling function, a pressure difference is generated between the upstream and downstream sides of the plurality of gas diffusion paths 42. This pressure difference enables the raw material gas 5 to be evenly supplied throughout the entire circumference of the gas buffer zone 41. At this time, the pressure difference between the upstream and downstream sides is preferably at least 70 Pa.

[0143] As described above, the active gas generating device 100 is characterized in that each gas diffusion path 42 is formed with a relatively small size so that the pressure of the gas buffer zone 41 as the internal gas flow path is higher than the pressure of the gas relay region R4.

[0144] The active gas generating device 100 according to the first embodiment has the above-described features, and can make the raw material gas 5 flow evenly throughout the entire circumference of the annular gas buffer zone 41 .

[0145] As a result, the active gas generator 100 of the first embodiment can supply the raw material gas uniformly flowing in the gas buffer zone 41 to the discharge space 6 via the plurality of gas diffusion paths 42 and the gas relay region R4 with relatively little variation. Therefore, the active gas generator 100 can generate the active gas 52 with relatively high generation efficiency.

[0146] As described above, the metal electrodes 10 and 20 are annular in plan view, so the discharge space 6 is annular inside the gas buffer zone 41 across the gas relay region R4 .

[0147] The plurality of discretely arranged gas diffusion paths 42 are provided at equal intervals along the formation direction of the gas buffer zone 41. Therefore, the active gas generating device 100 of the first embodiment can stably supply a predetermined amount of the raw material gas 5 to the discharge space 6 via the gas relay region R4.

[0148] As a result, the reactive gas generating device 100 according to the first embodiment can stably output a predetermined amount of reactive gas to the external processing space 63 through the gas ejection holes 23 and the gas ejection holes 43 .

[0149] (Insulation board 7)

[0150] Figure 9 Yes Figure 1 A plan view of the planar structure of the insulating plate 7 is shown, Figure 10 It is a cross-sectional view showing the cross-sectional structure of the insulating plate 7 . Figure 9 The D-D cross section is Figure 10 . Figure 9 as well as Figure 10 The XYZ orthogonal coordinate systems are recorded respectively.

[0151] As shown in the figure, the insulating plate 7 as an insulating material is formed into a circular shape in a plan view and has a through hole 71 penetrating the insulating plate 7. The through hole 71 is a passage for an electric wire that applies an AC voltage from the high-frequency power supply 50 to the metal electrode 10.

[0152] The insulating plate 7 is formed of an insulator such as alumina, SAPPHAL, or aluminum nitride, and is in close contact with the metal electrode 10 of the high voltage applying electrode unit 1 to remove discharge heat generated by the high voltage applying electrode unit 1 to the cooling plate 9 .

[0153] As will be described later, the insulating plate 7 has a region that overlaps with the cooling water path 90 , which is a cooling medium path of the cooling plate 9 , in a plan view.

[0154] The insulating plate 7 of the active gas generating device 100 has a region overlapping with the cooling water path 90 of the cooling plate 9 in a plan view. Therefore, the cooling plate 9 can efficiently cool the high-voltage applying electrode unit 1 as the first electrode component via the insulating plate 7 .

[0155] (Electrode pressing member 8)

[0156] Figure 11 Yes Figure 1 The plan view of the planar structure of the electrode pressing member 8 shown, Figure 12 It is a cross-sectional view showing the cross-sectional structure of the electrode pressing member 8 . Figure 11 The E-E section is Figure 12 . Figure 11 as well as Figure 12 The XYZ orthogonal coordinate systems are recorded respectively.

[0157] like Figure 1 As shown, the metal electrode support member, or electrode pressing member 8, is used to press the upper electrode assembly, including the high-voltage applying electrode unit 1 and the insulating plate 7, from below. It has a circular ring shape when viewed from above. The electrode pressing member 8 has a pressing protrusion 8a that protrudes downward toward the inner circumference. Specifically, the pressing protrusion 8a has a circular ring shape when viewed from above.

[0158] like Figure 11 as well as Figure 12 As shown, the pressing protrusion 8a of the electrode pressing member 8 is provided so as to protrude toward the inner side of the electrode dielectric film 11 by a predetermined protrusion length, and the upper surface of the pressing protrusion 8a contacts a part of the lower surface of the electrode dielectric film 11. Figure 12 As shown, the protruding direction of the pressing protrusion 8a is parallel to the horizontal plane (XY plane).

[0159] (Cooling Plate 9)

[0160] Figure 13 Yes Figure 1 A plan view of the planar structure of the cooling plate 9 is shown, Figure 14 It is a cross-sectional view showing the cross-sectional structure of the cooling plate 9 . Figure 13 The F-F section is Figure 14 . Figure 13 as well as Figure 14 The XYZ orthogonal coordinate systems are recorded respectively.

[0161] like Figure 1 、 Figure 13 as well as Figure 14As shown, the cooling plate 9 as a conductive structure has a cooling water path 90 therein. The cooling water path 90 is a region through which cooling water flowing in from a cooling water supply port 92 passes, and the cooling water is discharged from a cooling water discharge port 93 .

[0162] Furthermore, the cooling plate 9 has a portion having a current-carrying hole 91 extending therethrough. The current-carrying hole 91 extends through the cooling plate 9 and serves as a passage for an electrical wire that applies an AC voltage from the high-frequency power supply 50 to the metal electrode 10. Thus, the electrical wire can be connected from the high-frequency power supply 50 to the metal electrode 10 via the current-carrying hole 91 in the cooling plate 9 and the current-carrying hole 71 in the insulating plate 7. Furthermore, the current-carrying hole 91 has a sufficiently large opening so that the electrical wire is not electrically connected to the cooling plate 9.

[0163] Cooling water supply port 92 is provided at a position where cooling water supplied from cooling water passage port 451 can flow in. Cooling water discharge port 93 is provided at a position where cooling water discharged from cooling water path 90 can be supplied to cooling water passage port 452 of base flange 4 .

[0164] Therefore, in the base flange 4 , the cooling water through port 451 is used to supply cooling water to the cooling water path 90 of the cooling plate 9 , and the cooling water through port 452 is used to discharge cooling water from the cooling plate 9 to the outside through the base flange 4 .

[0165] like Figure 1 、 Figure 13 as well as Figure 14 As shown, most of the cooling plate 9 except for the current-passing holes 91 serves as the cooling water path 90. Therefore, the insulating plate 7 has a region that overlaps with most of the cooling water path 90 of the cooling plate 9 in a plan view.

[0166] In this way, since the insulating plate 7 of the active gas generating device 100 has an area that overlaps with most of the cooling water path 90 of the cooling plate 9 when viewed from above, the cooling plate 9 can perform a cooling function by efficiently cooling the high voltage applying electrode part 1 through the insulating plate 7 by the cooling water flowing in the cooling water path 90.

[0167] (Comparison with other devices)

[0168] Figure 30 1 is a cross-sectional view showing the overall structure of an active gas generating device 100X of a first comparative device. Figure 31 It is a cross-sectional view of the entire structure of an active gas generating device 100Y of a second comparative device. Figure 30 as well as Figure 31 The XYZ coordinate systems are recorded separately.

[0169] like Figure 30As shown, the first comparative active gas generating device 100X has a ground potential electrode portion 102 (metal electrode 120 + electrode dielectric film 121) disposed on the central bottom surface area of ​​the base flange 104, and a high voltage application electrode portion 101 (metal electrode 110 + electrode dielectric film 111) disposed on the peripheral protrusion of the base flange 104. The contact surface between the high voltage application electrode portion 101 and the base flange 104 is sealed.

[0170] Then, the source gas 105 is supplied toward the discharge space 106 from a gas supply port 140 provided on a side surface of a peripheral protrusion of the base flange 104 .

[0171] In the active gas generating device 100X, the raw material gas 105 supplied from the gas supply port 140 is supplied to the discharge space 106 and then discharged as the active gas 152 through the gas ejection holes 123 of the electrode dielectric film 121 and the gas ejection holes 143 of the base flange 104 .

[0172] In the active gas generating device 100X as well, the electrode dielectric film 111 of the high voltage applying electrode unit 101 separates the gas flow 151 of the raw material gas 105 between the case inner space 133 in the metal case 103 and the discharge space 106 .

[0173] However, the active gas generator 100X does not have a cooling mechanism equivalent to the cooling plate 9 and therefore cannot increase the discharge power density in the discharge space 6 beyond a certain level. Consequently, there is a problem in that the amount of active gas 152 generated cannot be increased.

[0174] like Figure 31 As shown, in the second comparative active gas generating device 100Y, a ground potential electrode portion 202 (metal electrode 220 + electrode dielectric film 221) is disposed on the central bottom surface area of ​​the base flange 204. A high voltage application electrode portion 201 (metal electrode 210 + electrode dielectric film 211) is disposed on the central protruding area of ​​the base flange 204. The contact surface between the high voltage application electrode portion 201 and the base flange 204 is sealed. Furthermore, an insulating plate 207 is disposed on the high voltage application electrode portion 201.

[0175] Furthermore, a cooling plate 209 is provided on a protruding region of the end portion of the base flange 204. Thus, the base flange 204 is formed in a stepped shape from the center to the peripheral portion when viewed in cross section.

[0176] Furthermore, the raw material gas 205 is supplied from a gas supply port 240 provided on one side surface of the base flange 204 , and cooling water is supplied to the cooling plate 209 from a cooling water supply port 244 provided on the other side surface of the base flange 204 .

[0177] In the active gas generating device 100Y, the source gas 205 supplied from the gas supply port 240 is supplied to the discharge space 206 and then discharged as active gas 252 through the gas ejection holes 223 of the electrode dielectric film 221 and the gas ejection holes 243 of the base flange 204 .

[0178] In the active gas generating device 100Y, the high voltage applying electrode unit 201, the insulating plate 207, and the cooling plate 209 also separate the flow 251 of the source gas 205 between the housing interior space 233 within the metal housing 203 and the discharge space 206. Furthermore, the active gas generating device 100Y cools the high voltage applying electrode unit 201 using the cooling plate 209.

[0179] However, the active gas generating device 100Y does not include a mechanism corresponding to the electrode pressing member 8 of the first embodiment, and therefore has a structure in which the cooling plate 209 is attached to the base flange 204 via the high voltage applying electrode unit 201 and the insulating plate 207 .

[0180] In this case, the height direction positioning of the cooling plate 209 needs to be carried out in accordance with the formed height (first dimension) of the end protruding area of ​​the base flange 204, and in accordance with the combined film thickness (second dimension) of the overlapping parts of the high voltage application electrode part 201 and the insulating plate 207.

[0181] Therefore, there is a problem that when a deviation occurs between the first and second dimensions, leakage of cooling water or raw material gas 205 may occur.

[0182] The above-mentioned problem will be described in detail below. Here, the first dimension is defined as the step D1 and the second dimension is defined as the thickness D2.

[0183] When the thickness D2 is smaller than the step D1, gas leakage occurs. When the cooling plate 9 is bolted to the base flange 4, the high-voltage electrode unit 201 is pressed against the base flange 204 via the insulating plate 207. As a result, the O-ring (not shown) between the high-voltage electrode unit 201 and the base flange 204 collapses, forming a seal.

[0184] Thus, the high-voltage electrode unit 201 is not directly attached to the base flange 204. This is because if the high-voltage electrode unit 201 is directly attached to the base flange 204 using dedicated fastening bolts, the outer diameters of the high-voltage electrode unit 201 and the base flange 204 would be further increased to ensure space for the fastening bolts, which is not practical.

[0185] However, if the thickness D2 is smaller than the step D1, the high voltage applying electrode unit 1 is not pressed sufficiently against the base flange 4, resulting in insufficient crushing of the O-ring therebetween. Furthermore, the possibility of a gap forming between the insulating plate 207 and the cooling plate 209 increases.

[0186] As a result, there is a high possibility that gaps will be generated between the high voltage applying electrode unit 1 and the base flange 4 and between the insulating plate 207 and the cooling plate 209 , and thus there is a possibility that leakage of cooling water or the raw material gas 205 may occur.

[0187] Thus, in the first and second comparative structures without at least one of the insulating plate 7 , the electrode pressing member 8 , and the cooling plate 9 of the first embodiment, problems arise and the effects of the active gas generator 100 of the first embodiment cannot be achieved.

[0188] <Implementation Method 2>

[0189] Figure 15 1 is a plan view showing the planar structure of the base flange 4B according to the second embodiment. Figure 16 It is a cross-sectional view showing the cross-sectional structure of the base flange 4B. Figure 17 : is an explanatory diagram schematically showing the characteristics of the diffusion path formation direction of the gas diffusion path 42B. Figure 15 The G-G cross section is Figure 16 . Figure 15 as well as Figure 16 The XYZ orthogonal coordinate systems are recorded respectively.

[0190] The active gas generating device 100B of the second embodiment has the same structure as the active gas generating device 100 of the first embodiment, except that the base flange 4 is replaced with a base flange 4B. The following description will focus on the base flange 4B.

[0191] (Base flange 4B)

[0192] like Figures 15 to 17 As shown, like the base flange 4, the base flange 4B is circular in plan view and has a gas ejection hole 43 (base flange gas ejection hole) in the center. The gas ejection hole 43 penetrates the base flange 4B. Furthermore, the base flange 4B, which is made of metal and conductive, is grounded.

[0193] The gas buffer zone 41, which is the internal gas flow path, is connected to the gas passage 35 and is formed into a ring shape in a plan view so as to surround the gas relay region R4. Figure 15 as well as Figure 16 As shown, the gas buffer area 41 has a groove structure in which grooves are formed when viewed in cross section, and thus can temporarily accommodate the raw material gas 5 .

[0194] A plurality of gas diffusion paths 42B are discretely provided between the gas buffer zone 41 and the gas relay region R4, forming an internal gas flow path. Therefore, the raw material gas 5 flows from the gas buffer zone 41 to the gas relay region R4 via the plurality of gas diffusion paths 42B.

[0195] like Figure 15 As shown, the plurality of gas diffusion paths 42B are discretely provided at equal intervals along the formation direction (circumferential direction) of the gas buffer zone 41 .

[0196] By setting the formation width and formation depth of the gas diffusion path 42B to be sufficiently small, the gas diffusion path 42B can be endowed with a throttling function similarly to the gas diffusion path 42 .

[0197] like Figure 16 As shown, in the base flange 4B, the raw material gas 5 entering from the gas supply port 34 passes through the gas passage 35. The raw material gas 5 is supplied to the entire circumference of the gas buffer zone 41, which is a groove formed in an annular shape in a plan view.

[0198] The raw material gas 5 temporarily retained in the gas buffer zone 41 then flows to the gas relay region R4 via the plurality of gas diffusion paths 42B. By forming the plurality of gas diffusion paths 42B as relatively small, restrictive grooves, a pressure difference is generated between the upstream and downstream sides of the gas diffusion paths 42B. This pressure difference enables the gas to be evenly supplied throughout the entire circumference of the gas buffer zone 41. The pressure difference between the upstream and downstream sides is preferably at least 70 Pa.

[0199] Here, the center position of the annular gas buffer zone 41 is set as the imaginary center point PC. The imaginary center point PC also becomes the center point of the gas ejection hole 43. Figure 17 As shown, a line extending from a connection position P41 of each gas diffusion path 42B with the gas buffer zone 41 toward the virtual center point PC is referred to as a virtual center line LC.

[0200] The second embodiment is characterized in that the path angle θ42 of the diffusion path formation direction D42 of each of the plurality of gas diffusion paths 42B relative to the imaginary center line LC is set to be in the range of 30° to 60°. Furthermore, the path angle θ42 is preferably set to be the same angle among the plurality of gas diffusion paths 42B.

[0201] The active gas generating device 100B of the second embodiment has the above-mentioned features. Therefore, the raw material gas 5 supplied from the plurality of gas diffusion paths 42B to the gas relay region R4 swirls, and the raw material gas 5 can be uniformly supplied to the discharge space 6 without unevenness within the gas relay region R4.

[0202] As a result, the active gas generating device 100B according to the second embodiment can generate the active gas 52 at a higher generation efficiency.

[0203] The above effects are described in detail below. Figure 6 As shown in the gas diffusion path 42 of embodiment 1, when a gas diffusion path 42 is set with the direction toward the imaginary center point PC as the diffusion path formation direction, that is, when the path angle of the diffusion path formation direction relative to the imaginary center line LC is 0°, when the raw gas 5 is supplied from the gas diffusion path 42 to the gas relay region R4, the flow of the raw gas 5 will generate turbulence.

[0204] If the turbulent flow is not eliminated by the discharge space 6 , the generation efficiency of the active gas 52 in the discharge space 6 may be deteriorated.

[0205] on the other hand, Figure 15 as well as Figure 17 The gas diffusion path 42B shown has a path angle θ42 set within the range of 45°±15° relative to the imaginary center line LC. Therefore, the flow of the raw material gas 5 becomes a vortex state and flows more evenly into the discharge space 6, so that the flow of the raw material gas 5 does not generate turbulence.

[0206] Furthermore, when the path angle θ42 is 45°, it can be expected that the possibility of generating turbulence in the flow of the raw material gas 5 can be minimized.

[0207] Furthermore, similar to the first embodiment, the active gas generating device 100B of the second embodiment has a gas separation structure that separates the flow of gas between the housing inner space 33 and the discharge space 6 by at least the cooling plate 9 , the electrode pressing member 8 , and the high-voltage applying electrode unit 1 .

[0208] The active gas generating device 100B of the second embodiment includes the above-described gas separation structure, and thus, similarly to the first embodiment, can discharge high-quality active gas 52 that does not contain impurities.

[0209] Furthermore, similarly to the first embodiment, the active gas generating device 100B includes the insulating plate 7 and the cooling plate 9 , and thus the amount of generated active gas 52 can be increased.

[0210] In addition to this, the base flange 4B of the active gas generating device 100B includes a gas buffer zone 41 having the same features as those of the first embodiment.

[0211] Therefore, the active gas generating device 100B can supply the raw material gas 5 in a uniform eddy flow to the discharge space 6 via the plurality of gas diffusion paths 42B and the gas relay region R4 , and can therefore generate the active gas 52 with high generation efficiency.

[0212] In addition, the plurality of discretely arranged gas diffusion paths 42B are arranged at equal intervals along the formation direction of the gas buffer zone 41 , so that, as in the first embodiment, a predetermined amount of generated active gas can be stably output to the outside through the gas ejection holes 23 and the gas ejection holes 43 .

[0213] <Implementation Method 3>

[0214] (First Problem of Implementation Method 1)

[0215] In the active gas generating device 100 of the first embodiment, the discharge space 6 is located relatively close to the gas ejection holes 23. Consequently, a first problem arises: dielectric breakdown occurs between the gas ejection holes 23 and the base flange 4, causing the elements constituting the base flange 4 to vaporize, becoming a source of contamination. This is because, compared to the ceramics constituting the electrode dielectric films 11 and 21, the metal constituting the base flange 4 is more susceptible to vaporization when exposed to discharge.

[0216] An apparatus intended to solve the first problem of the first embodiment is an active gas generating apparatus 100C of the third embodiment described below.

[0217] (Overall composition)

[0218] Figure 18 It is an explanatory diagram showing the overall structure of an active gas generating device according to Embodiment 3 of the present invention. Figure 18 The XYZ orthogonal coordinate system is described in . The active gas generating device 100C of the third embodiment generates active gas 52 obtained by activating the raw material gas 5 supplied to the discharge space 6C.

[0219] The active gas generating device 100C includes, as main components, a metal casing 3 , a base flange 4 , a high voltage applying electrode portion 1C, a ground potential electrode portion 2C, an insulating plate 7C, an electrode pressing member 8 , a cooling plate 9 , and an auxiliary metal electrode 12 .

[0220] The base flange 4 has a concave cross-section and includes a central bottom region 48 and a peripheral protrusion 46 extending along the periphery of the central bottom region 48 and protruding in the height direction (+Z direction).

[0221] The metal case 3 is a metal case having an opening at the bottom. The metal case 3 mainly includes a case inner space 33 for accommodating the cooling plate 9 .

[0222] The metal housing 3 is fixed to the base flange 4, with the metal base flange 4 serving as its bottom surface. Specifically, the metal housing 3 is fixed to the peripheral protrusion 46 of the base flange 4. Therefore, the opening of the metal housing 3 is shielded by the base flange 4, and the metal housing 3 and the base flange 4 form a shielded space including the housing interior space 33. Furthermore, the metal housing 3 is set to ground potential via the base flange 4.

[0223] A cooling plate 9 is disposed on the bottom portion of the housing interior space 33 in the active gas generating device 100C. Specifically, the cooling plate 9 is disposed on the upper surface of the peripheral protrusion 46 of the base flange 4 so that the peripheral end of the cooling plate 9 contacts the upper surface of the peripheral protrusion 46 of the base flange 4. At this time, the cooling plate 9 is disposed so as not to contact the metal housing 3. The cooling plate 9 is a conductive structure made of metal and has electrical conductivity.

[0224] On the other hand, a ground potential electrode portion 2C, serving as a second electrode component, is disposed on the central bottom region 48 of the base flange 4. The ground potential electrode portion 2C primarily comprises an electrode dielectric film 21, serving as a second electrode dielectric film, and a metal electrode 20C, serving as a second metal electrode, formed on the lower surface of the electrode dielectric film 21. Therefore, the ground potential electrode portion 2C is placed on the central bottom region 48 such that the metal electrode 20C contacts the central bottom region 48.

[0225] The combination of the high voltage applying electrode section 1C as the first electrode component and the ground potential electrode section 2C as the second electrode component forms an electrode pair having a discharge space 6C therein. The ground potential electrode section 2C is provided below the high voltage applying electrode section 1C.

[0226] The high voltage applying electrode portion 1C includes, as main components, an electrode dielectric film 11 as a first electrode dielectric film and a metal electrode 10C as a first metal electrode formed on the upper surface of the electrode dielectric film 11 .

[0227] An AC voltage is applied between the metal electrode 10C and the metal electrode 20C from the high frequency power supply 50 . Specifically, the AC voltage is applied to the metal electrode 10C from the high frequency power supply 50 , and the metal electrode 20C is set to the ground potential via the base flange 4 .

[0228] In a closed space serving as a dielectric space where the electrode dielectric film 11 and the electrode dielectric film 21 face each other, a discharge space 6C is provided including a region where the metal electrodes 10C and 20C overlap in a plan view.

[0229] The electrode dielectric film 21 has gas ejection holes 23 for ejecting active gas 52 into the lower (latter) processing space 63 through the gas ejection holes 43 of the susceptor flange 4. Therefore, the path from the discharge space 6C to the gas ejection holes 23 is defined as the active gas flow path.

[0230] Furthermore, an auxiliary metal electrode 12 serving as a third metal electrode is provided on the upper surface of the electrode dielectric film 11. The auxiliary metal electrode 12 is provided independently of the metal electrode 10C. Therefore, the auxiliary metal electrode 12 and the metal electrode 10C are not electrically connected.

[0231] The auxiliary metal electrode 12 is provided so as to overlap with a portion of the active gas flow path in a plan view, and is set to a ground potential as will be described in detail later.

[0232] A gas ejection hole 43 (base flange gas ejection hole) is provided in the central portion of the central bottom region 48 of the base flange 4 at a position corresponding to the gas ejection hole 23 of the electrode dielectric film 21 without interposing the metal electrode 20C therebetween.

[0233] As described above, the cooling plate 9 is fixed to the peripheral protrusion 46 of the base flange 4. The insulating plate 7C is provided on the lower surface of the cooling plate 9. The high voltage applying electrode unit 1C is arranged so that the upper surface of the metal electrode 10C contacts the lower surface of the insulating plate 7C.

[0234] An electrode pressing member 8, serving as an electrode support member, is provided on the lower surface of the cooling plate 9. The electrode pressing member 8 is provided in the outer peripheral region of the insulating plate 7C and the high-voltage applying electrode unit 1C. In the third embodiment, the combined structure of the insulating plate 7C, the high-voltage applying electrode unit 1C, and the auxiliary metal electrode 12 is sometimes referred to simply as the "upper electrode group."

[0235] The electrode pressing member 8 has a pressing protrusion 8a protruding inwardly (in the direction of formation of the upper electrode group) at its lower portion. The pressing protrusion 8a is provided so as to protrude inwardly in the horizontal direction (XY plane) so that its upper surface contacts the lower surface of the electrode dielectric film 11 .

[0236] The upper electrode group is fixed to the lower surface of the cooling plate 9 by sandwiching the upper electrode group between the pressing protrusions 8 a of the electrode pressing member 8 and the cooling plate 9 .

[0237] Therefore, the electrode pressing member 8 functions as an electrode supporting member provided on the lower surface of the cooling plate 9 so as to support the high-voltage applying electrode unit 1C from below.

[0238] Thus, the electrode pressing member 8 is attached to the lower surface of the cooling plate 9 so as to sandwich the upper electrode group between the pressing protrusion 8a and the cooling plate 9. As in the first embodiment, the electrode pressing member 8 is attached to the cooling plate 9 using stainless steel bolts.

[0239] The plate-shaped insulating plate 7C, which is an insulating material, is provided between the cooling plate 9, the high voltage applying electrode unit 1C, and the auxiliary metal electrode 12. Its upper surface contacts the lower surface of the cooling plate 9, and its lower surface contacts the metal electrode 10C of the high voltage applying electrode unit 1C.

[0240] Therefore, the cooling plate 9 is positioned above the high-voltage applying electrode unit 1C without being in contact with the high-voltage applying electrode unit 1C via the insulating plate 7C.

[0241] As described above, the active gas generating device 100C has the following mounting feature: the high voltage applying electrode portion 1C is not placed above the ground potential electrode portion 2C via a spacer, but is mounted on the upper cooling plate 9 .

[0242] The active gas generating device 100C has the above-described mounting features, so that the height direction positioning of the cooling plate 9 can be determined solely by the contact surface with the peripheral protrusion 46 of the base flange 4. In other words, the height direction positioning of the cooling plate 9 can be determined solely by the height of the upper surface of the peripheral protrusion 46 of the base flange 4.

[0243] Therefore, the active gas generating device 100C can completely prevent gas leakage and cooling water leakage between the cooling plate 9 and the base flange 4 by accurately setting the formation position of the cooling plate 9 .

[0244] In addition to the electrical through-holes 71, the insulating plate 7C also has through-holes 72 for electrically connecting the cooling plate 9 to the auxiliary metal electrode 12. The through-holes 72 are provided in a region that overlaps with the auxiliary metal electrode 12 when viewed from above. Therefore, the auxiliary metal electrode 12 can be electrically connected to the cooling plate 9 relatively easily via the through-holes 72.

[0245] Specifically, it is conceivable to provide an electrical connection component for electrically connecting the insulating plate 7 and the auxiliary metal electrode 12 in the through-hole 72. For example, a conductive spring such as a metal spring (not shown) is arranged in the through-hole 72, and the upper end of the spring is brought into contact with the lower surface of the cooling plate 9, and the lower end of the spring is brought into contact with the upper surface of the auxiliary metal electrode 12. As a result, the cooling plate 9 and the auxiliary metal electrode 12 can be electrically connected by the spring as the electrical connection component. In this way, by providing an electrically conductive spring or other electrical connection component in the through-hole 72 of the insulating plate 7C, the cooling plate 9 and the auxiliary metal electrode 12 can be electrically connected.

[0246] The base flange 4 has a gas supply port 34 on one side surface of the peripheral protrusion 46 and a gas passage 35 therein. The source gas 5 supplied from the outside flows through the gas supply port 34 into the gas passage 35 .

[0247] Furthermore, the base flange 4 has a gas relay region R4 above the central bottom region 48 (and mainly below the electrode pressing member 8 ) serving as a relay region for the raw material gas 5 between the gas passage 35 and the discharge space 6C.

[0248] Therefore, the raw material gas 5 flowing through the gas passage 35 is eventually supplied to the discharge space 6C via the gas relay region R4. Specifically, a gas buffer region 41 and a gas diffusion path 42 exist between the gas passage 35 and the gas relay region R4.

[0249] As described above, the susceptor flange 4 includes a gas supply port 34 for receiving the source gas 5 from the outside, and a gas passage 35 for supplying the source gas 5 to the discharge space 6C.

[0250] The gas relay region R4 is completely separated from the housing internal space 33 by the high voltage applying electrode portion 1C (first electrode component), the insulating plate 7C (insulating material), the electrode pressing member 8 , and the cooling plate 9 .

[0251] In order to achieve the above-mentioned complete separation, the contact surface between the cooling plate 9 and the base flange 4, the contact surface between the cooling plate 9 and the electrode pressing component 8, and the contact surface between the electrode pressing component 8 and the high voltage applying electrode part 1C are respectively sealed based on O-rings (the O-rings are not shown).

[0252] Therefore, the gas flow between the housing inner space 33 and the discharge space 6C is separated by at least the electrode pressing member 8 , the cooling plate 9 , and the high-voltage applying electrode unit 1C.

[0253] That is, the raw material gas 5 flowing in the gas relay region R4 does not mix into the housing inner space 33 , and conversely, impurities and the like present in the housing inner space 33 do not mix into the discharge space 6C via the gas relay region R4 .

[0254] The base flange 4 has a cooling water supply port 44 on the other side of the peripheral protrusion 46 . Cooling water as a cooling medium supplied from the outside flows through the peripheral protrusion 46 and is supplied to the cooling plate 9 from the cooling water passage port 451 .

[0255] The cooling plate 9 has a cooling water path 90 as a cooling medium path inside, through which cooling water supplied via the cooling water passage port 451 flows. Therefore, the cooling plate 9 has a cooling function of cooling the high-voltage applying electrode portion 1C (electrode dielectric film 11) via the insulating plate 7C by flowing cooling water through the cooling water path 90.

[0256] As described above, the base flange 4 includes the cooling water supply port 44 as a cooling medium supply port for receiving cooling water as a cooling medium, and the cooling water passage port 451 as a cooling medium passage port for supplying cooling water to the cooling plate 9 .

[0257] Hereinafter, a brief description will be given of the steps for installing the active gas generating device 100C having the above-described structure.

[0258] (1) The cooling plate 9 is turned over so that the relationship between the upper surface and the lower surface of the cooling plate 9 is reversed.

[0259] (2) The insulating plate 7C is arranged at the center of the lower surface of the cooling plate 9 .

[0260] (3) Make the spring conductive (in Figure 18 The insulating plate 7C (not shown) is disposed in the center portion of the lower surface of the cooling plate 9 through the through hole 72 of the insulating plate 7C.

[0261] (4) An auxiliary metal electrode 12 is arranged on the spring.

[0262] (5) The high voltage applying electrode portion 1C is placed on the insulating plate 7C in this order, followed by the metal electrode 10C and the electrode dielectric film 11 .

[0263] (6) The electrode pressing member 8 is placed on the lower surface of the cooling plate 9, and bolts are tightened between the cooling plate 9 and the electrode pressing member 8. As a result, the upper electrode group is attached to the lower surface of the cooling plate 9. At this time, the space between the cooling plate 9 and the electrode pressing member 8, and the space between the high-voltage applying electrode unit 1C and the electrode pressing member 8 are sealed.

[0264] (7) The ground potential electrode portion 2C is placed on the central bottom surface region 48 of the base flange 4 .

[0265] (8) The cooling plates 9 to which the upper electrode group is attached are returned to their original vertical relationship.

[0266] (9) The cooling plate 9 is placed on the peripheral protrusion 46 of the base flange 4, and bolts are fastened between the cooling plate 9 and the base flange 4. At this time, the cooling plate 9 and the base flange 4 are sealed.

[0267] Thus, through the assembly steps (1) to (9), the active gas generating device 100C of embodiment 3 can be assembled. In order to perform step (3), the through hole 72 of the insulating plate 7C is shaped larger than the diameter of the spring for electrically connecting the auxiliary metal electrode 12 to the cooling plate 9.

[0268] In the active gas generating device 100C assembled as described above, the raw material gas 5 is supplied into the susceptor flange 4 from the gas supply port 34 provided on one side surface of the peripheral protrusion 46 of the susceptor flange 4 .

[0269] Within the peripheral protrusion 46 of the susceptor flange 4, a flow 51 of the raw material gas 5 flows from the gas passage 35 through the gas buffer zone 41 (described later) and the gas diffusion path 42 toward the gas relay region R4. Gas flow 51 then flows from the gas relay region R4 toward the discharge space 6C between the high-voltage application electrode portion 1C and the ground potential electrode portion 2C. Passing the raw material gas 5 through the discharge space 6C, to which discharge power is applied, activates the raw material gas 5, producing an active gas 52. The active gas 52 is supplied to the processing space 63 below through the gas ejection holes 23 and 43.

[0270] At this time, the space 33 inside the housing can be set to a pressure from the atmospheric pressure of around 100 kPa to 1×10 －1 Pa~1×10 －3 The wide pressure range up to a high vacuum of about Pa. In particular, when the housing inner space 33 is brought to a high vacuum, even if a very small amount of leakage occurs between the housing inner space 33 and the discharge space 6C, all of it will leak toward the housing inner space 33, thus having the advantage of not affecting the object to be processed.

[0271] The active gas generating device 100C of the third embodiment is characterized in that it has a gas separation structure that separates the flow of gas between the housing inner space 33 and the discharge space 6C by the cooling plate 9 , the insulating plate 7C, the electrode pressing member 8 , and the high voltage applying electrode unit 1C.

[0272] Furthermore, separation of the gas flow between the housing inner space 33 and the discharge space 6C can be achieved by providing at least the cooling plate 9 , the electrode pressing member 8 , and the high-voltage applying electrode unit 1C.

[0273] The active gas generating device 100C of the third embodiment has a gas separation structure similar to the first embodiment, and can reliably prevent impurities generated in the housing inner space 33 from entering the discharge space 6C.

[0274] As a result, the active gas generating device 100C of the third embodiment can discharge high-quality active gas 52 containing no impurities without damaging the electrode dielectric films 11 and 21 , similarly to the first embodiment.

[0275] Furthermore, the cooling plate 9, a conductive structure, has a cooling water path 90 serving as a cooling medium path, thereby providing a cooling function. The cooling function of the cooling plate 9 allows the high-voltage applying electrode unit 1C to be cooled via the insulating plate 7C (insulating material). Consequently, the temperature difference between regions within the dielectric film 11 (first electrode dielectric film) having the lower surface forming the discharge space 6C can be minimized.

[0276] Therefore, the active gas generating device 100C of the third embodiment suppresses the temperature difference between the regions in the dielectric film, thereby increasing the discharge power applied to the discharge space 6C, thereby increasing the amount of active gas 52 generated.

[0277] Furthermore, by providing the insulating plate 7C between the cooling plate 9 and the metal electrode 10C, a short circuit phenomenon in which the metal electrode 10C and the cooling plate 9 are electrically connected can be reliably avoided, as in the first embodiment.

[0278] (High voltage applying electrode portion 1C)

[0279] Figure 19 Yes Figure 18 The plan view of the upper surface structure of the high voltage applying electrode portion 1C and the auxiliary metal electrode 12 is shown. Figure 20 It is a cross-sectional view showing the cross-sectional structure of the high-voltage applying electrode section 1C and the auxiliary metal electrode 12 . Figure 19 The H-H cross section becomes Figure 20 . Figure 19 as well as Figure 20 The XYZ orthogonal coordinate systems are recorded respectively.

[0280] like Figures 18 to 20 As shown, the electrode dielectric film 11 of the high voltage applying electrode portion 1C has a circular shape in a plan view.

[0281] Metal electrode 10C is provided on the upper surface of electrode dielectric film 11 and is formed into a ring shape having a circular opening 15C at the center. The diameter of opening 15C of metal electrode 10C is shorter than the diameter of opening 15 of metal electrode 10 in the first embodiment. Accordingly, the formation area of ​​metal electrode 10C is larger than that of metal electrode 10 in the first embodiment.

[0282] The auxiliary metal electrode 12 is provided in a small circular shape at the center of the upper surface of the electrode dielectric film 11. Since an opening 15C exists between the auxiliary metal electrode 12 and the metal electrode 10C, the auxiliary metal electrode 12 and the metal electrode 10C are electrically independent.

[0283] (Ground Potential Electrode Section 2C)

[0284] Figure 21 Yes Figure 18 The plan view of the lower surface structure of the ground potential electrode portion 2C shown in FIG. Figure 22 2C is a cross-sectional view showing the cross-sectional structure of the ground potential electrode portion 2C. Figure 21 The I-I section becomes Figure 22 . Figure 21 as well as Figure 22 The XYZ orthogonal coordinate systems are recorded respectively.

[0285] like Figure 18 、 Figure 21 as well as Figure 22 As shown, the electrode dielectric film 21 of the ground potential electrode portion 2C has a circular shape in a plan view.

[0286] The metal electrode 20C is provided on the lower surface of the electrode dielectric film 21 and is formed into a ring shape having a circular opening 25C at the center. The diameter of the opening 25C of the metal electrode 20C is shorter than the diameter of the opening 25 of the metal electrode 20 in the first embodiment. Accordingly, the formation area of ​​the metal electrode 20C is larger than that of the metal electrode 20 in the first embodiment.

[0287] The metal electrode 20C is formed so as to entirely encompass the metal electrode 10C in a plan view. Therefore, the discharge space 6C where the metal electrodes 20C and 10C overlap in a plan view is substantially defined by the formation region of the metal electrode 10C.

[0288] Therefore, discharge space 6C, like metal electrode 10C, is formed in a circular shape in a plan view with gas ejection hole 23 as the center. Compared with discharge space 6 in embodiment 1, discharge space 6C extends closer to gas ejection hole 23 and has a larger spatial volume than discharge space 6.

[0289] The ground potential electrode portion 2C has a gas ejection hole 23 at the center thereof for ejecting the active gas 52 generated in the discharge space 6C downward. The gas ejection hole 23 is formed to penetrate the electrode dielectric film 21 .

[0290] like Figure 21 As shown, the gas ejection hole 23 is provided at the center position of the opening 25C of the metal electrode 20C so as not to overlap with the metal electrode 20C in a plan view.

[0291] Therefore, the auxiliary metal electrode 12 serving as the third metal electrode is provided in the opening 15C in a region overlapping with the gas ejection holes 23 in a plan view.

[0292] On this basis, the metal electrode 10C can achieve a shorter distance from the gas ejection hole 23 in a plan view compared to the metal electrode 10 of Embodiment 1. Similarly, the metal electrode 20C can achieve a shorter distance from the gas ejection hole 23 compared to the metal electrode 20 of Embodiment 1.

[0293] Therefore, in the active gas generating device 100C of the third embodiment, the discharge space 6C is extended to a position closer to the gas ejection holes 23 than the discharge space 6. Accordingly, the distance of the active gas flow path from the discharge space 6C to the gas ejection holes 23, i.e., the active gas flow distance, is shortened.

[0294] Furthermore, by setting the hole diameter of the gas ejection hole 23 to be sufficiently small, the gas ejection hole 23 can be given a throttling function, similarly to the first embodiment.

[0295] (Base flange 4)

[0296] The structure of the base flange 4 Figures 6 to 8 The base flange 4 of the illustrated embodiment 1 is identical.

[0297] (Insulation board 7C)

[0298] Figure 23 Yes Figure 18 The plan view of the planar structure of the insulating plate 7C shown, Figure 24 It is a cross-sectional view showing the cross-sectional structure of the insulating plate 7C. Figure 23 The J-J cross section becomes Figure 24 . Figure 23 as well as Figure 24The XYZ orthogonal coordinate systems are recorded respectively.

[0299] like Figure 23 As shown, the insulating plate 7C is circular in plan view and has a portion thereof having a through hole 71 and a through hole 72. The through hole 71 serves as a passage for an electric wire that applies an AC voltage from the high-frequency power supply 50 to the metal electrode 10C.

[0300] A through hole 72, which is circular in shape when viewed from above, is provided through the center of the insulating plate 7C and, as described above, is provided for arranging electrical connection components such as a conductive spring therein. As described above, the diameter of the through hole 72 is set to be longer than the diameter of the spring used to electrically connect the auxiliary metal electrode 12 to the cooling plate 9.

[0301] The insulating plate 7C is formed of an insulator such as alumina, SHAPAL, or aluminum nitride. The insulating plate 7C is structured to remove discharge heat generated in the high voltage applying electrode unit 1C to the cooling plate 9 by being in close contact with the metal electrode 10C of the high voltage applying electrode unit 1C.

[0302] As in the first embodiment, the insulating plate 7C has a region that overlaps with the cooling water path 90 , which is a cooling medium path of the cooling plate 9 , in a plan view.

[0303] (Electrode pressing member 8)

[0304] The structure of the electrode pressing member 8 is Figure 11 as well as Figure 12 The electrode pressing member 8 is the same as that of the first embodiment shown.

[0305] (Cooling Plate 9)

[0306] The structure of the cooling plate 9 as a conductive structure is similar to Figure 13 as well as Figure 14 The cooling plate 9 is the same as that of the first embodiment shown.

[0307] (Effect)

[0308] The active gas generating device 100C of the third embodiment has the following effects in addition to the same effects as those of the first embodiment.

[0309] The active gas generating device 100C of the third embodiment includes an auxiliary metal electrode 12 set to ground potential. Therefore, the potential around the auxiliary metal electrode 12 is reduced. The auxiliary metal electrode 12 is close to the active gas flow path, thus lowering the potential of the active gas flow path.

[0310] Therefore, the active gas generating device 100C can relax the electric field intensity in the active gas flow path, so that even when the diameter of the discharge space 6C and the gas ejection hole 23 is short, the base flange 4 does not suffer insulation breakdown.

[0311] As a result, the active gas generating apparatus 100C of the third embodiment can intentionally reduce the electric field intensity in the processing space 63 provided below the gas ejection holes 43 without changing the arrangement and structure of the gas ejection holes 23 and 43 .

[0312] Hereinafter, the above-mentioned effects of the active gas generating device 100C according to Embodiment 3 will be described in detail. As described above, the active gas generating device 100C has the following features (1) and (2).

[0313] (1) The auxiliary metal electrode 12 is provided so as to overlap with a portion of the active gas flow path in a plan view.

[0314] (2) The auxiliary metal electrode 12 is set to the ground potential.

[0315] The active gas generating device 100C of the third embodiment has the above-mentioned features (1) and (2), and can relax the electric field intensity in the active gas flow path by the auxiliary metal electrode 12 which is the third metal electrode set to the ground potential.

[0316] As a result, the active gas generating device 100C of the third embodiment achieves the following main effect: the electric field intensity in the processing space 63 located below the gas ejection hole 43 can be intentionally reduced without changing the structure of the gas ejection holes 23 and 43, which serve as the throttle portion. Furthermore, along with this main effect, the following first to fourth ancillary effects can be achieved.

[0317] A first additional effect is that the generation of abnormal discharge in the processing space 63 can be suppressed, the generation of metal contamination in the processing space 63 can be suppressed, and damage to processing objects such as wafers in the processing space 63 can be reduced.

[0318] Second additional effect: The metal electrodes 10C and 20C can be arranged so that the distance of the active gas flow path, that is, the active gas flow distance, can be further shortened.

[0319] As a result, the active gas generating apparatus 100C of the third embodiment can efficiently supply the active gas 52 to the processing space 63 without increasing the electric field intensity in the processing space 63. Furthermore, the active gas flow distance can be shortened, thereby enabling the miniaturization of the active gas generating apparatus 100C.

[0320] Furthermore, as a method of shortening the active gas flow distance, the third embodiment adopts a structure in which the diameter of the opening 15C of the metal electrode 10C is shortened to bring the inner periphery of the metal electrode 10C closer to the center.

[0321] A third additional effect is that the length of the gas ejection holes 23 and 43 serving as the throttle portion can be shortened.

[0322] As a result, the active gas generating apparatus 100C of the third embodiment can efficiently supply the active gas 52 to the processing space 63 without increasing the electric field intensity in the processing space 63. Furthermore, the formation lengths of the gas ejection holes 23 and 43 can be shortened, thereby enabling the miniaturization of the active gas generating apparatus 100C.

[0323] Fourth additional effect: The AC voltage applied by the high-frequency power supply 50 can be increased. As a result, the active gas generating apparatus 100C of the third embodiment can supply a large amount of active gas 52 to the processing space 63 without increasing the electric field intensity in the processing space 63 .

[0324] Furthermore, the active gas generating device 100C of the third embodiment, by having the aforementioned gas separation structure, requires less need to improve the close contact between the metal electrode 10C and the auxiliary metal electrode 12 and the upper surface of the electrode dielectric film 11. This is because even if the lower surface of the metal electrode 10C, which is made of bulk metal, is distorted and a microscopic space is created between the lower surface of the metal electrode 10C and the upper surface of the electrode dielectric film 11, discharge does not occur in this microscopic space.

[0325] When the auxiliary metal electrode 12 is made of bulk metal, the auxiliary metal electrode 12 can be relatively easily disposed on the spring serving as the electrical connection member, as in step (3) of the above-mentioned mounting step.

[0326] Similarly, when a bulk metal is used for the metal electrode 10C, the process of placing the metal electrode 10C on the insulating plate 7C can be performed relatively simply as in step (5) of the above-mentioned mounting process.

[0327] In this manner, bulk metal that is relatively easy to manufacture can be used as the metal electrode 10C and the auxiliary metal electrode 12 , and accordingly, the manufacturing process of the active gas generating device 100C can be simplified.

[0328] Furthermore, in the third embodiment, the active gas flow distance of the active gas flow path is set to be relatively short.

[0329] Therefore, the active gas generating device 100C of the third embodiment can effectively suppress the phenomenon of active gas decaying (disappearing) and deactivating over time by reducing the spatial volume of the active gas flow path compared to the spatial volume of the active gas flow path in the first embodiment.

[0330] Furthermore, in the active gas generating device 100C of the third embodiment, by providing the insulating plate 7C between the cooling plate 9 and the metal electrode 10C, a short circuit phenomenon in which the metal electrode 10C and the cooling plate 9 are electrically connected can be reliably avoided.

[0331] In the active gas generating device 100C of the third embodiment, the auxiliary metal electrode 12 is electrically connected to the cooling plate 9 as a conductive structure via the through hole 72 of the insulating plate 7C. Therefore, the auxiliary metal electrode 12 can be stably set to the ground potential via the base flange 4 and the cooling plate 9.

[0332] Specifically, as described above, by providing a conductive spring in the through-hole 72 and achieving electrical connection between the auxiliary metal electrode 12 and the cooling plate 9, the auxiliary metal electrode 12 can be set to ground potential via the spring, the cooling plate 9, and the base flange 4. The spring serves as an electrical connection member.

[0333] In the active gas generating device 100C of the third embodiment, the circular auxiliary metal electrode 12 is provided in the opening 15C of the metal electrode 10C in a region overlapping with the gas ejection holes 23 in a plan view.

[0334] That is, the auxiliary metal electrode 12 is arranged so that the center position of the opening 15C coincides with the center position of the auxiliary metal electrode 12. Therefore, the auxiliary metal electrode 12 can be electrically independent from the metal electrode 10C while maintaining a relatively large shape.

[0335] This is because the center position of the opening 15C is the position farthest from the inner peripheral portion of the metal electrode 10C.

[0336] As a result, the active gas generating device 100C according to the third embodiment can maximize the effect of relaxing the electric field intensity in the active gas flow path.

[0337] <Implementation Method 4>

[0338] (Second Problem of Implementation Method 1)

[0339] In the active gas generating device 100 of the first embodiment, an active gas flow path exists between the discharge space 6 and the gas ejection holes 23 .

[0340] The time it takes for the active gas to pass through the active gas flow path increases in proportion to the spatial volume of the active gas flow path. Therefore, there is a second problem that it is difficult to completely suppress the phenomenon of active gas decaying (disappearing) and becoming inactive over time.

[0341] The active gas generating device 100D of the fourth embodiment described below actively overcomes the second problem of the above-mentioned embodiment 1. In addition, the active gas generating device 100C of the third embodiment solves the second problem by shortening the active gas flow distance.

[0342] (Overall composition)

[0343] Figure 25 It is an explanatory diagram showing the overall structure of an active gas generating device according to a fourth embodiment of the present invention. Figure 25 An XYZ orthogonal coordinate system is described in . The active gas generating device 100D of the fourth embodiment generates active gas 52 obtained by activating the raw material gas 5 supplied to the discharge space 6 .

[0344] The active gas generating device 100D includes as main components a metal casing 3 , a base flange 4 , a high voltage applying electrode unit 1 , a ground potential electrode unit 2D, an insulating plate 7C, an electrode pressing member 8 , a cooling plate 9 , and an auxiliary metal electrode 12 .

[0345] In addition, the high voltage applying electrode unit 1, the metal housing 3, the base flange 4, the electrode pressing member 8 and the cooling plate 9 are connected to the Figures 1 to 3 、 Figures 6 to 8 、 Figure 13 as well as Figure 14 The active gas generating device 100 of the illustrated embodiment 1 is the same as that of the active gas generating device 100. Therefore, the same reference numerals are assigned and the description thereof is omitted as appropriate.

[0346] In addition, the insulating plate 7C and the auxiliary metal electrode 12 are Figure 18 、 Figure 23 as well as Figure 24 The active gas generating device 100C of the third embodiment shown is the same as that shown in FIG. Therefore, the same reference numerals are given and the description thereof is omitted as appropriate.

[0347] Hereinafter, the description will be focused on the characteristic parts of the active gas generating device 100D according to the fourth embodiment.

[0348] A ground potential electrode portion 2D, serving as a second electrode component, is disposed on the central bottom region 48 of the base flange 4. The ground potential electrode portion 2D primarily comprises an electrode dielectric film 21D, serving as a second electrode dielectric film, and a metal electrode 20, serving as a second metal electrode, formed on the lower surface of the electrode dielectric film 21D. Therefore, the ground potential electrode portion 2D is placed on the central bottom region 48 so that the metal electrode 20 contacts the central bottom region 48.

[0349] The combination of the high voltage applying electrode section 1 as the first electrode component and the ground potential electrode section 2D as the second electrode component constitutes an electrode pair having a discharge space 6 therein. The ground potential electrode section 2D is provided below the high voltage applying electrode section 1 .

[0350] The high voltage applying electrode unit 1 includes, as main components, an electrode dielectric film 11 as a first electrode dielectric film and a metal electrode 10 as a first metal electrode formed on the upper surface of the electrode dielectric film 11 .

[0351] An AC voltage is applied between the metal electrode 10 and the metal electrode 20 from the high-frequency power supply 50. Specifically, the AC voltage is applied to the metal electrode 10 from the high-frequency power supply 50, and the metal electrode 20 is set to the ground potential via the base flange 4. Furthermore, as in the third embodiment, the auxiliary metal electrode 12 is set to the ground potential via the base flange 4, the cooling plate 9, and the electrical connection member provided in the through-hole 72 of the insulating plate 7C.

[0352] In a closed space serving as a dielectric space where the electrode dielectric film 11 and the electrode dielectric film 21 face each other, a discharge space 6 is provided including a region where the metal electrodes 10 and 20 overlap in a plan view.

[0353] The electrode dielectric film 21D has gas ejection holes 23D for ejecting active gas 52 into the lower (latter) processing space 63 through the gas ejection holes 43 of the susceptor flange 4. Therefore, the path from the discharge space 6 to the gas ejection holes 23D defines an active gas flow path.

[0354] The electrode dielectric film 21D has a protrusion 21a that protrudes in the height direction to partially fill the active gas flow path. Therefore, the active gas flow path is narrowed to a narrow path between the upper surface of the protrusion 21a and the lower surface of the electrode dielectric film 11.

[0355] Furthermore, similar to the third embodiment, the active gas generating device 100D of the fourth embodiment includes an auxiliary metal electrode 12 as a third metal electrode on the upper surface of the electrode dielectric film 11. The auxiliary metal electrode 12 is formed independently of the metal electrode 10.

[0356] The auxiliary metal electrode 12 is provided so as to overlap with a portion of the active gas flow path in a plan view. Similarly to the third embodiment, the auxiliary metal electrode 12 is set to the ground potential.

[0357] A gas ejection hole 43 (base flange gas ejection hole) is provided in the center of the central bottom region 48 of the base flange 4 at a position corresponding to the gas ejection hole 23D of the electrode dielectric film 21D without interposing the metal electrode 20 .

[0358] As described above, the cooling plate 9 is fixed to the peripheral protrusion 46 of the base flange 4. The insulating plate 7C is provided on the lower surface of the cooling plate 9, and the high voltage applying electrode unit 1 is arranged so that the upper surface of the metal electrode 10 contacts the lower surface of the insulating plate 7C.

[0359] An electrode pressing member 8, serving as an electrode support member, is provided on the lower surface of the cooling plate 9. The electrode pressing member 8 is provided in the outer peripheral region of the insulating plate 7C and the high-voltage applying electrode unit 1. In the fourth embodiment, the combined structure of the insulating plate 7C, the high-voltage applying electrode unit 1, and the auxiliary metal electrode 12 is sometimes referred to simply as the "upper electrode group."

[0360] A plate-shaped insulating plate 7C, serving as an insulating material, is disposed between the cooling plate 9 and the high-voltage applying electrode unit 1. Its upper surface contacts the lower surface of the cooling plate 9, and its lower surface contacts the upper surface of the metal electrode 10 of the high-voltage applying electrode unit 1. As in the third embodiment, the insulating plate 7C has, in addition to the electrical through-holes 71, through-holes 72 for electrically connecting the cooling plate 9 to the auxiliary metal electrode 12.

[0361] Hereinafter, a brief description will be given of the steps for installing the active gas generating device 100D having the above-described structure.

[0362] (1) The cooling plate 9 is turned over so that the relationship between the upper surface and the lower surface of the cooling plate 9 is reversed.

[0363] (2) A metal and conductive spring is arranged at the center of the lower surface of the cooling plate 9 ( Figure 25 (illustration omitted).

[0364] (3) An auxiliary metal electrode 12 is arranged on the spring.

[0365] (4) The insulating plate 7C is placed on the lower surface of the cooling plate 9. At this time, the auxiliary metal electrode 12 passes through the through hole 72 of the insulating plate 7C, and the spring is located in the through hole 72 provided in the insulating plate 7C.

[0366] (5) The high-voltage applying electrode unit 1 is placed on the insulating plate 7C in this order, followed by the metal electrode 10 and the electrode dielectric film 11 .

[0367] (6) The electrode pressing member 8 is placed on the lower surface of the cooling plate 9, and bolts are tightened between the cooling plate 9 and the electrode pressing member 8. As a result, the upper electrode group is attached to the lower surface of the cooling plate 9. At this time, the space between the cooling plate 9 and the electrode pressing member 8, and between the high-voltage applying electrode unit 1 and the electrode pressing member 8, is sealed.

[0368] (7) The ground potential electrode portion 2D is placed on the central bottom surface region 48 of the base flange 4 .

[0369] (8) Return the cooling plates 9 to which the upper electrode group is mounted to their original vertical relationship.

[0370] (9) The cooling plate 9 is placed on the peripheral protrusion 46 of the base flange 4, and bolts are fastened between the cooling plate 9 and the base flange 4. At this time, the space between the cooling plate 9 and the base flange 4 is sealed.

[0371] In this manner, the active gas generating device 100D of the fourth embodiment can be assembled through the assembly steps (1) to (9).

[0372] The active gas generating device 100D of the fourth embodiment is characterized in that it has a gas separation structure that separates the flow of gas between the housing inner space 33 and the discharge space 6 by the cooling plate 9 , the insulating plate 7C, the electrode pressing member 8 , and the high-voltage applying electrode unit 1 .

[0373] As in the first embodiment, the active gas generating device 100D of the fourth embodiment has a gas separation structure, and can discharge high-quality active gas 52 containing no impurities without damaging the electrode dielectric films 11 and 21D.

[0374] (High voltage applying electrode section 1)

[0375] Figure 26 Yes Figure 25 The plan view of the upper surface structure of the high voltage applying electrode unit 1 and the auxiliary metal electrode 12 is shown. Figure 27 It is a cross-sectional view showing the cross-sectional structure of the high-voltage applying electrode unit 1 and the auxiliary metal electrode 12 . Figure 26 The K-K cross section becomes Figure 27 . Figure 26 as well as Figure 27The XYZ orthogonal coordinate systems are recorded respectively.

[0376] like Figures 25 to 27 As shown, the electrode dielectric film 11 of the high-voltage applying electrode unit 1 has a circular shape in a plan view.

[0377] The metal electrode 10 is provided on the upper surface of the electrode dielectric film 11 and is formed in an annular shape having a circular opening 15 at the center, similarly to the first embodiment.

[0378] The auxiliary metal electrode 12 is provided at the center of the upper surface of the electrode dielectric film 11 and is formed into a small circular shape. Since an opening 15 exists between the auxiliary metal electrode 12 and the metal electrode 10, the auxiliary metal electrode 12 and the metal electrode 10 are electrically independent.

[0379] (Ground Potential Electrode Section 2D)

[0380] Figure 28 Yes Figure 25 The plan view of the lower surface structure of the ground potential electrode portion 2D shown in FIG. Figure 29 2D is a cross-sectional view showing the cross-sectional structure of the ground potential electrode portion 2D. Figure 28 The L-L section becomes Figure 29 . Figure 28 as well as Figure 29 The XYZ orthogonal coordinate systems are recorded respectively.

[0381] like Figure 25 、 Figure 28 as well as Figure 29 As shown, the electrode dielectric film 21D of the ground potential electrode portion 2D has a circular shape in a plan view.

[0382] The metal electrode 20 is provided on the lower surface of the electrode dielectric film 21D and, similarly to the first embodiment, is formed in an annular shape having a circular opening 25 at the center.

[0383] The metal electrode 20 is formed so as to entirely encompass the metal electrode 10 in a plan view. Therefore, the discharge space 6 where the metal electrode 20 and the metal electrode 10 overlap in a plan view is substantially defined by the region where the metal electrode 10 is formed. Therefore, like the metal electrode 10, the discharge space 6 is formed in an annular shape centered on the gas ejection hole 23D in a plan view.

[0384] like Figure 29 As shown, the electrode dielectric film 21D has a protrusion 21a protruding in the height direction (+Z direction) so as to fill a portion of the active gas flow path in a region corresponding to the opening 25 of the metal electrode 20 in a plan view.

[0385] like Figure 29As shown, in the electrode dielectric film 21D, the region where the protrusion 21a is formed is referred to as the protrusion formation region RT, and the region other than the protrusion formation region RT is referred to as the dielectric film main region RM. Furthermore, the length of the protrusion 21a that protrudes in the height direction (+Z direction) from the upper surface of the dielectric film main region RM is referred to as the protrusion length of the protrusion 21a.

[0386] The protruding length of the protrusion 21a is set to be slightly shorter than the distance (gap length) between the lower surface of the electrode dielectric film 11 and the upper surface of the dielectric film main region RM of the electrode dielectric film 21D. Therefore, a slight gap (hereinafter sometimes referred to as "active gas flow gap") is provided between the upper surface of the protrusion 21a and the lower surface of the electrode dielectric film 11 of the high-voltage applying electrode unit 1.

[0387] Thus, in the active gas generating device 100D of the fourth embodiment, the protrusion 21a of the electrode dielectric film 21D fills a portion of the active gas flow path in the dielectric space, thereby limiting at least a portion of the active gas flow path to a narrow active gas flow gap.

[0388] That is, the protrusion 21 a functions as an active gas assisting structure provided to fill a portion of the active gas flow path between the discharge space 6 and the gas ejection holes 23 in the dielectric space.

[0389] The ground potential electrode portion 2D has a gas ejection hole 23D at its center for ejecting the active gas 52 generated in the discharge space 6 downward. The gas ejection hole 23D is formed through the protrusion 21a of the electrode dielectric film 21D. Because the gas ejection hole 23D is formed through the protrusion 21a, it has a longer length than the gas ejection hole 23 in the first embodiment.

[0390] like Figure 28 As shown, the gas ejection hole 23D is provided at the center position of the opening 25 of the metal electrode 20 so as not to overlap with the metal electrode 20 in a plan view.

[0391] Therefore, the auxiliary metal electrode 12 serving as the third metal electrode is provided in the opening 15 in a region overlapping with the gas ejection hole 23D in a plan view.

[0392] Furthermore, by setting the hole diameter of the gas ejection hole 23D to be sufficiently small, the gas ejection hole 23D can be given a throttling function, similarly to the first embodiment.

[0393] (Base flange 4)

[0394] The structure of the base flange 4 Figures 6 to 8The base flange 4 of the illustrated embodiment 1 is identical.

[0395] (Insulation board 7C)

[0396] The structure of the insulating plate 7C is Figure 23 as well as Figure 24 The insulating plate 7C is the same as that of the third embodiment shown.

[0397] Therefore, the insulating plate 7C has a conducting hole 71 and a through hole 72. The through hole 72 is provided through the center of the insulating plate 7C and is provided for arranging an electrically connecting component such as a conductive spring inside.

[0398] (Electrode pressing member 8)

[0399] The structure of the electrode pressing member 8 is Figure 11 as well as Figure 12 The electrode pressing member 8 is the same as that of the first embodiment shown.

[0400] (Cooling Plate 9)

[0401] The structure of the cooling plate 9 as a conductive structure is similar to Figure 13 as well as Figure 14 The cooling plate 9 is the same as that of the first embodiment shown.

[0402] (Effect)

[0403] Similar to the third embodiment, the active gas generating device 100D of the fourth embodiment includes an auxiliary metal electrode 12 set to a ground potential. Therefore, the active gas generating device 100D of the fourth embodiment can intentionally reduce the electric field intensity in the processing space 63 located below the gas ejection holes 43 without changing the arrangement and structure of the gas ejection holes 23D and the gas ejection holes 43.

[0404] On this basis, the active gas generating device 100D of embodiment 4 has the above-mentioned gas separation structure, so that, similar to embodiment 3, relatively easy-to-manufacture bulk metal can be used as the metal electrode 10 and the auxiliary metal electrode 12, thereby simplifying the manufacturing process accordingly.

[0405] In the active gas generating device 100D of the fourth embodiment, the auxiliary metal electrode 12 is electrically connected to the cooling plate 9 as a conductive structure via the through hole 72 of the insulating plate 7C. Therefore, as in the third embodiment, the auxiliary metal electrode 12 can be stably set to the ground potential.

[0406] In the active gas generating device 100D of the fourth embodiment, the circular auxiliary metal electrode 12 is provided within the opening 15 of the metal electrode 10 in a region that overlaps with the gas ejection holes 23D when viewed from above. This allows the auxiliary metal electrode 12 to be electrically independent from the metal electrode 10 while maintaining a relatively large size.

[0407] As a result, similarly to the third embodiment, the active gas generating device 100D of the fourth embodiment can maximize the effect of relaxing the electric field intensity in the active gas flow path.

[0408] Furthermore, the electrode dielectric film 21D of the active gas generating device 100D of the fourth embodiment has a protrusion 21a as a dielectric protrusion as a unique feature. The protrusion 21a functions as an active gas auxiliary structure that fills a portion of the active gas flow path.

[0409] Therefore, the active gas generating device 100D of embodiment 4 is a device that fills a portion of the above-mentioned active gas flow path with the protrusion 21a, and accordingly, the spatial volume in the above-mentioned active gas flow path can be narrowed, and the time for the active gas to pass through the above-mentioned active gas flow path can be shortened to a level that the active gas is not deactivated.

[0410] As a result, the active gas generating device 100D according to the fourth embodiment exhibits an effect of being able to suppress the deactivation amount of active gas to a necessary minimum.

[0411] Furthermore, in the fourth embodiment, the protrusion 21 a is formed as a part of the electrode dielectric film 21D, and therefore, the active gas assisting structure can be realized without increasing the number of components.

[0412] Therefore, the active gas generating device 100D of the fourth embodiment can be manufactured through substantially the same assembly steps as those of the third embodiment. Therefore, the active gas generating device 100D of the fourth embodiment can suppress the deactivation amount of active gas to the necessary minimum without complicating the manufacturing process.

[0413] Furthermore, by making the active gas flow gap formed on the upper surface of the protrusion 21a sufficiently narrow, that is, by making the length of the raw gas flow gap in the height direction (Z direction) sufficiently short, the active gas flow gap can be given a throttling function. By providing the active gas flow gap with a throttling function, a pressure difference can be created between the processing space 63 in the downstream (lower) stage of the active gas generating device 100D and the discharge space 6, thereby sufficiently reducing the pressure in the processing space 63.

[0414] At this time, the electric field intensity in the processing space 63 is set to be sufficiently low, so that insulation breakdown can be prevented even in the processing space 63 under a relatively low pressure environment.

[0415] <Other>

[0416] Furthermore, in the above embodiment, water is shown as the cooling medium supplied to the cooling water passage 90 , but other cooling media such as heat transfer fluid (GALDEN) may also be used.

[0417] Furthermore, in the fourth embodiment, the protrusion 21a is provided as a part of the electrode dielectric film 21D, but a dielectric auxiliary component may be used as a component separate from the electrode dielectric film 21. For example, a modification is conceivable in which the dielectric auxiliary component is disposed on the upper surface of the electrode dielectric film 21 that does not have the protrusion 21a in a region corresponding to the opening 15 in a plan view.

[0418] In the modified example, the thickness of the dielectric auxiliary member is set to be shorter than the distance (gap length) between the electrode dielectric films 11 and 21. Therefore, the gap for the active gas flow is provided between the upper surface of the dielectric auxiliary member and the lower surface of the electrode dielectric film 11 of the high-voltage applying electrode unit 1.

[0419] By providing the dielectric auxiliary member on the upper surface of the electrode dielectric film 21 , a portion of the active gas flow path can be filled in the dielectric space between the discharge space 6 and the gas ejection holes 23 to limit the active gas flow gap.

[0420] As a result, the dielectric auxiliary member functions as an active gas auxiliary structure that fills a portion of the active gas flow path between the discharge space 6 and the gas ejection holes 23 in the dielectric space, similarly to the protrusion 21 a .

[0421] However, the dielectric auxiliary member and the electrode dielectric film 21 are separate components, so the number of components increases. Therefore, in the modified example, the number of components increases, and accordingly, Figures 25 to 29 The manufacturing process of the fourth embodiment shown is more complicated.

[0422] While the present invention has been described in detail, the above description is in all aspects illustrative and the present invention is not limited thereto, and numerous modifications not shown in the examples are contemplated without departing from the scope of the present invention.

[0423] Explanation of symbols

[0424] 1. 1C high voltage application electrode part

[0425] 2, 2C, 2D Ground potential electrode

[0426] 3 Metal shell

[0427] 4.4B base flange

[0428] 5 Raw gas

[0429] 6. 6C discharge space

[0430] 7.7C Insulation board

[0431] 8 Electrode pressing parts

[0432] 9 Cooling Plate

[0433] 10, 10C, 20, 20C metal electrodes

[0434] 11, 21, 21D dielectric films for electrodes

[0435] 12 Auxiliary metal electrode

[0436] 21a protrusion

[0437] 23, 23D, 43 gas ejection holes

[0438] 34 Gas supply port

[0439] 35 Gas passage path

[0440] 41 Gas Buffer Zone

[0441] 42, 42B Gas Diffusion Path

[0442] 44 Cooling water supply port

[0443] 50 High Frequency Power Supply

[0444] 52 active gas

[0445] 72 through holes

[0446] 90 Cooling water path

[0447] 451, 452 Cooling water through port

[0448] R4 gas relay area

Claims

1. An active gas generating device for generating active gas by activating a raw material gas supplied to a discharge space, characterized in that: have: a first electrode forming portion; and The second electrode component is provided below the first electrode component. The first electrode-forming portion includes a first electrode dielectric film and a first metal electrode formed on the upper surface of the first electrode dielectric film. The second electrode-forming portion includes a second electrode dielectric film and a second metal electrode formed on the lower surface of the second electrode dielectric film. An AC voltage is applied to the first metal electrode, and the second metal electrode is set to a ground potential. Within the dielectric space where the first and second electrode dielectric films face each other, the discharge space includes a region where the first and second metal electrodes overlap in a plan view. The second electrode dielectric film has a gas ejection hole for ejecting the active gas downward, and a path from the discharge space to the gas ejection hole is defined as an active gas flow path. The active gas generating device further includes a base flange having a conductive structure and a concave cross-sectional structure, comprising a central bottom region and a peripheral protrusion provided along the periphery of the central bottom region and protruding in the height direction, wherein the second electrode forming portion is provided so that the second metal electrode contacts the central bottom region. The above-mentioned active gas generating device further comprises: a conductive structure having conductivity, provided on the peripheral protrusion of the base flange, and positioned above the first electrode component without contacting the first electrode component; an insulating material disposed between the conductive structure and the first electrode component, with its upper surface in contact with the lower surface of the conductive structure and its lower surface in contact with the upper surface of the first metal electrode; an electrode supporting member provided on the lower surface of the conductive structure so as to support the first electrode constituting portion from below; and The metal shell is provided on the peripheral protrusion of the base flange and has a shell inner space for accommodating the conductive structure. The base flange has: A gas supply port for receiving the above-mentioned raw material gas from the outside; a gas passage for supplying the raw material gas to the discharge space; and The base flange has a gas ejection hole for ejecting the above-mentioned active gas ejected from the above-mentioned gas ejection hole downward. The base flange is given ground potential, The conductive structure, the electrode support member, and the first electrode component are used to provide a gas separation structure for separating the flow of gas between the space inside the housing and the discharge space. The active gas generating device further comprises a third metal electrode provided on the upper surface of the first electrode dielectric film independently of the first metal electrode. The third metal electrode is provided so as to overlap with a portion of the active gas flow path in a plan view, and is set to a ground potential.

2. The active gas generating device according to claim 1, wherein: The insulating material has a through hole, and the through hole is provided in a region overlapping with the third metal electrode in a plan view. The third metal electrode is electrically connected to the conductive structure via the through hole.

3. The active gas generating device according to claim 1, wherein: The first metal electrode is formed into a ring shape having an opening at the center when viewed from above. The third metal electrode is formed into a circular shape when viewed from above. The third metal electrode is provided in the opening in a region overlapping with the gas ejection hole in a plan view.

4. The active gas generating device according to any one of claims 1 to 3, wherein: The active gas assist structure is further provided, wherein the active gas assist structure is provided in the dielectric space between the discharge space and the gas ejection hole so as to fill a portion of the active gas flow path.

5. The active gas generating device according to claim 4, wherein: The second electrode dielectric film has a dielectric protrusion protruding in a height direction so as to fill a portion of the active gas flow path. The dielectric protrusion functions as the active gas assist structure.

6. The active gas generating device according to any one of claims 1 to 3, wherein: The base flange also has: a cooling medium supply port for receiving a cooling medium from the outside; and a cooling medium passage port for supplying the cooling medium to the conductive structure; The conductive structure includes a cooling medium path therein, and the cooling medium path allows the cooling medium supplied through the cooling medium passage port to flow therein.

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