Plasma processing apparatus

Abstract

A plasma processing apparatus (100) for generating plasma in a vacuum container (1) by causing a high-frequency current to flow through an antenna (2) provided outside the vacuum container (1), the plasma processing apparatus (100) comprising: a slit plate (6) for closing an opening (1x) formed at a position facing the antenna (2) of the vacuum container (1); a dielectric plate (7) that closes a plurality of slit openings (6x) formed in the slit plate (6) from the outside of the vacuum container (1); a plurality of mask members (8) provided for each slit opening (6x) and covering the slit opening (6x) with a gap therebetween from the inside of the vacuum container (1); and a fixing mechanism (9) for fixing the plurality of mask members (8) corresponding to each of the slit openings (6x).

Description

Technical Field

[0001] The present invention relates to a plasma processing device for processing an object using plasma. Background Art

[0002] A plasma processing apparatus has been proposed in the past. This apparatus generates an inductively coupled plasma (ICP) by passing a high-frequency current through an antenna, generating an induced electric field. This inductively coupled plasma is then used to process substrates and other workpieces. Patent Document 1 discloses a plasma processing apparatus in which an antenna is positioned outside a vacuum chamber. The high-frequency magnetic field generated by the antenna is transmitted into the chamber through a magnetic field transmission window that blocks an opening in the sidewall of the chamber, thereby generating plasma within the chamber.

[0003] The plasma processing apparatus disclosed in Patent Document 1 includes a metal slit plate that blocks the opening of a vacuum chamber, and a dielectric plate that blocks the slit formed in the slit plate from the outside of the vacuum chamber. In this plasma processing apparatus, the metal slit plate and the dielectric plate superimposed on the slit plate function as a magnetic field transmission window. This reduces the thickness of the magnetic field transmission window compared to a case where only the dielectric plate functions as the magnetic field transmission window. This shortens the distance from the antenna to the interior of the vacuum chamber, allowing the high-frequency magnetic field generated by the antenna to be efficiently supplied to the vacuum chamber.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: International Publication No. 2020-188809 Summary of the Invention

[0007] Problems to be solved by the invention

[0008] However, in the structure of the plasma processing apparatus described in Patent Document 1, deposits generated by plasma near the slits or by particles trapped due to sputtering, etc., accumulate on the dielectric plate. If these deposits are conductive, the inner surface of the slits becomes conductive through the deposits. Consequently, due to the high-frequency magnetic field generated by the antenna, high-frequency current along the long sides of the antenna also flows through the slit plate, heating the dielectric plate due to the heat generated by the slit plate or the deposits. This can result in thermal deformation of the dielectric plate, or a reduction in strength due to chemical reactions between the dielectric plate and the deposits, raising concerns about damage to the dielectric plate.

[0009] To address this issue, the plasma processing apparatus of Patent Document 1 can be configured to cover the slits with a gap from the inside of the vacuum vessel using a mask plate formed of a flat plate. With this configuration, the mask plate covers the slits formed in the slit plate from the inside of the vacuum vessel, obscuring the dielectric plate when viewed from the inside of the vacuum vessel. This prevents conductive flying objects from adhering to the dielectric plate and causing contamination.

[0010] On the other hand, when including such a mask, the thickness of the mask is preferably thinner to avoid reducing the transmittance of the high-frequency magnetic field generated by the antenna. However, since the mask is a flat plate, making it thinner will cause the mask to warp and deform.

[0011] Furthermore, since the mask plate is heated by the heat of the generated plasma and the radiation from the workpiece generated by the plasma, it is ideally made of a heavy metal such as Mo or W, which has a low thermal expansion coefficient, to prevent deformation due to heat. Furthermore, in addition to the beam-shaped regions that cover the slits formed in the slit plate, the mask plate also has slits formed between the beam-shaped regions to allow the magnetic field to pass through. Since Mo and W are difficult to cut, cutting the mask plate to form slits is difficult, and this process is also costly.

[0012] The present invention is designed to solve the above-mentioned problems at one stroke. Its main subject is: in a plasma processing device in which an antenna is arranged outside a vacuum container and a dielectric plate and a slit plate are overlapped to form a magnetic field transmission window, the thickness of the mask member covering the slit formed in the slit plate is reduced and a material with a low thermal expansion coefficient is used for the mask member.

[0013] Technical means to solve the problem

[0014] That is, the plasma processing device of the present invention generates plasma in a vacuum container by passing a high-frequency current through an antenna provided outside the vacuum container. The plasma processing device is characterized in that it includes: a slit plate for blocking an opening formed in the vacuum container at a position facing the antenna; a dielectric plate for blocking a plurality of slit openings formed in the slit plate from the outside of the vacuum container; a plurality of mask members provided for each of the slit openings and covering the slit openings with gaps therebetween from the inside of the vacuum container; and a fixing mechanism for fixing the plurality of mask members corresponding to each of the slit openings.

[0015] With this structure, since masking members are placed at each slit opening, the size of each masking member is smaller than in a mask plate that covers the slit plate with a flat plate. This reduces the risk of warping during processing, allowing the masking member to be thinner. Consequently, a decrease in the transmittance of the high-frequency magnetic field generated by the antenna can be minimized.

[0016] In addition, since the mask member is set for each slit opening, there is no need to cut the mask member in a manner to form the slit, so heavy metals such as Mo or W with a small thermal expansion coefficient can be used as the material of the mask member, thereby suppressing the deformation of the mask member caused by heating.

[0017] Preferably, the slit opening is in a rectangular shape having a long side direction in a direction intersecting the antenna, the mask member is arranged from one end to the other end in the long side direction of the slit opening and is in the shape of a long strip, and the fixing mechanism includes: a pressing member that presses the mask member toward the slit plate; and an interlocking portion formed on the pressing member or the slit plate, which is interlocked with the end of the mask member in the long side direction.

[0018] With this structure, the mask member is positioned by the interlocking portion, thereby suppressing displacement of the mask member when the pressing member is pressing the mask member. Furthermore, since the mask member is arranged along the longitudinal direction of the slit opening, the mask member can be fixed corresponding to the slit opening, preventing conductive flying objects from adhering to the dielectric plate and causing contamination.

[0019] An example of a configuration is one in which a plurality of mask members are provided for each of the slit openings, and the plurality of mask members provided for the slit openings are provided with gaps therebetween to cover the slit openings.

[0020] If this structure is used, the width of each mask member along the long side of the antenna becomes smaller compared to the case where a single mask member is used to cover the slit opening, thereby reducing the induced current generated in each mask member and further suppressing the reduction in the transmittance of the high-frequency magnetic field.

[0021] In addition, since the plurality of mask members are provided with gaps therebetween, it is possible to suppress variations in plasma density that may be generated along the antenna due to contact between the plurality of mask members.

[0022] The following structures can be listed: the mask member is equipped with multiple strips along the long side direction of the antenna for each slit opening, and the lengths in the long side direction are different from each other. In the thickness direction of the slit plate, the mask member that is longer in the long side direction is arranged toward the inner side of the vacuum container. The fitting portion also includes a plurality of recesses, which are arranged along the long side direction of the antenna and are respectively fitted with the end portions of each mask member, and are arranged to: utilize a connecting wall formed by connecting adjacent parts of the plurality of recesses and an opposing wall arranged opposite to the connecting wall to clamp the end portion of the mask member that is longer in the long side direction.

[0023] With this structure, each mask member is fixed in the longitudinal direction of the antenna by the connecting wall and the facing wall, thereby preventing the mask members from shifting in the longitudinal direction of the antenna. In particular, when a mask member that is longer in the longitudinal direction is mounted on the slit plate, the mask member can be prevented from falling off the slit plate.

[0024] Furthermore, because adjacent portions of the plurality of recesses are connected, the plurality of masking members provided for each slit opening are positioned without gaps when viewed from the inside of the vacuum container. Consequently, when viewed from the inside of the vacuum container, the plurality of masking members provided for each slit opening cover the dielectric plate without gaps, thereby preventing conductive flying objects from adhering to the dielectric plate and causing contamination.

[0025] In the plasma processing apparatus, a shielding wall is provided in a gap between the slit plate and the mask member, and the shielding wall shields charged particles moving along the longitudinal direction of the antenna.

[0026] With this structure, the shielding wall can suppress the movement of charged particles in the gap along the longitudinal direction of the antenna, thereby preventing the generation of plasma between the mask member and the slit plate.

[0027] Effects of the Invention

[0028] According to the present invention thus constructed, in a plasma processing apparatus in which an antenna is arranged outside a vacuum container and a dielectric plate and a slit plate are overlapped to form a magnetic field transmission window, the thickness of the mask member covering the slit formed in the slit plate can be reduced and a material with a low thermal expansion coefficient can be used for the mask member. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] [ Figure 1 ] is a cross-sectional view schematically showing the structure of a plasma processing device according to one embodiment.

[0030] [ Figure 2] is a stereoscopic diagram of the structure near the magnetic field transmission window of the embodiment observed from the inside of the vacuum container.

[0031] [ Figure 3 ] is a decomposed stereoscopic diagram showing the structure near the magnetic field transmission window of the embodiment.

[0032] [ Figure 4 ] is a plan view of the structure near the magnetic field transmission window of the embodiment observed from the inside of the vacuum container.

[0033] [ Figure 5 (a) Yes Figure 4 (b) is a partially enlarged view of the AA line cross-sectional view, and (b) is a partially enlarged view of the B part of the AA line cross-sectional view.

[0034] [ Figure 6 ]yes Figure 4 BB line cross-section diagram.

[0035] [ Figure 7 ] is a plan view of the structure near the magnetic field transmission window of another embodiment observed from the inside of the vacuum container.

[0036] [ Figure 8 (a) Yes Figure 7 (b) is a partially enlarged view of the AA line cross-sectional view, and (b) is a partially enlarged view of the B part of the AA line cross-sectional view.

[0037] [ Figure 9 ]yes Figure 7 BB line cross-section diagram.

[0038] [ Figure 10 ] is a plan view of the structure near the magnetic field transmission window of another embodiment observed from the inside of the vacuum container.

[0039] [ Figure 11 (a) Yes Figure 10 AA line cross-sectional view, (b) is when the pressing member is removed Figure 10 An enlarged stereogram of the enlarged portion of part B.

[0040] [ Figure 12 ] is a cross-sectional view showing the structure near the magnetic field transmission window when the area between the antenna and the fixing mechanism is cut along the long side direction of the antenna in another embodiment. DETAILED DESCRIPTION

[0041] An embodiment of the plasma processing apparatus of the present invention is described below with reference to the accompanying drawings. In each of the following figures, for ease of understanding, the following diagrams may be schematically depicted with appropriate omissions or exaggerations. Identical components are denoted by the same reference numerals, and their descriptions are omitted as appropriate.

[0042] <Device Structure>

[0043] The plasma processing apparatus 100 of this embodiment uses inductively coupled plasma P to process a substrate O. Here, the substrate O is, for example, a substrate for a flat panel display (FPD) such as a liquid crystal display or an organic electroluminescence (EL) display, or a flexible substrate for a flexible display. Furthermore, the processing performed on the substrate O includes, for example, film formation using plasma chemical vapor deposition (CVD), etching, ashing, sputtering, and the like.

[0044] In addition, the plasma processing device 100 is also called a plasma CVD device when film formation is performed by the plasma CVD method, is also called a plasma etching device when etching is performed, is also called a plasma ashing device when ashing is performed, and is also called a plasma sputtering device when sputtering is performed.

[0045] Specifically, if Figure 1 As shown, plasma processing apparatus 100 includes a vacuum vessel 1 that is evacuated and into which a gas is introduced; an antenna 2 that is disposed outside vacuum vessel 1; and a high-frequency power supply 3 that applies a high frequency to antenna 2. In this configuration, the high frequency power supply 3 applies a high frequency to antenna 2, causing a high-frequency current IR to flow through antenna 2, thereby generating an induced electric field within vacuum vessel 1 and generating inductively coupled plasma P.

[0046] The vacuum container 1 is a container made of metal, for example, and has an opening 1x formed in its wall (here, the upper wall 1a) extending through the wall in the thickness direction. The vacuum container 1 is electrically grounded, and its interior is evacuated by a vacuum exhaust device 4.

[0047] In addition, gas is introduced into the vacuum container 1, for example, via a flow rate regulator (not shown) or one or more gas inlet ports 11 provided in the vacuum container 1. The gas may be a gas corresponding to the processing content to be performed on the substrate O. For example, when a film is formed on the substrate by a plasma CVD method, the gas is a raw material gas or a gas diluted with a dilution gas (e.g., H2). To give further specific examples, when the raw material gas is SiH4, a Si film can be formed on the substrate; when the raw material gas is SiH4+NH3, a SiN film can be formed on the substrate; when the raw material gas is SiH4+O2, a SiO2 film can be formed on the substrate; and when the raw material gas is SiF4+N2, a SiN:F film (silicon nitride fluoride film) can be formed on the substrate.

[0048] A substrate holder 5 is provided within the vacuum container 1 to hold a substrate O. As in the example described above, a bias voltage may be applied to the substrate holder 5 from a bias power supply 12. Examples of the bias voltage include, but are not limited to, a negative DC voltage or a negative bias voltage. This bias voltage can be used to control the energy of positive ions in the plasma P incident on the substrate O, thereby controlling the crystallinity of the film formed on the surface of the substrate O. A heater 51 may be provided within the substrate holder 5 to heat the substrate O.

[0049] like Figure 1 As shown, the antenna 2 is arranged so as to face the opening 1x formed in the vacuum container 1. The number of antennas 2 is not limited to one, and a plurality of antennas 2 may be provided.

[0050] The high-frequency power supply 3 can flow a high-frequency current IR through the antenna 2 via the matching circuit 31. The frequency of the high-frequency power is, for example, generally 13.56 MHz, but is not limited thereto and can be changed as appropriate.

[0051] The plasma processing apparatus 100 further includes: a slit plate 6 for blocking an opening 1x formed in a wall (upper wall 1a) of the vacuum container 1 from the outside of the vacuum container 1; a dielectric plate 7 for blocking a slit opening 6x formed in the slit plate 6 from the outside of the vacuum container 1; a plurality of mask members 8 for each slit opening 6x provided and covering each slit opening 6x with a gap G therebetween from the inside of the vacuum container 1; and a fixing mechanism 9 for fixing the plurality of mask members 8 corresponding to each slit opening.

[0052] The slit plate 6 allows the high-frequency magnetic field generated by the antenna 2 to penetrate the vacuum vessel 1 while preventing the electric field from entering the interior of the vacuum vessel 1 from outside. Specifically, the slit plate 6 is flat and has multiple slit openings 6x extending through its thickness. The slit openings 6x are rectangular in shape, with their longitudinal sides extending in a direction intersecting the antenna 2. The slit plate 6 preferably has a higher mechanical strength than the dielectric plate 7 (described later) and preferably has a greater thickness than the dielectric plate 7. When viewed in the thickness direction, the multiple slit openings 6x are parallel to each other and formed so as to intersect (specifically, orthogonally) with the antenna 2. That is, a beam-shaped region 6z is formed between the multiple slit openings 6x, parallel to each slit opening 6x. The multiple slit openings 6x all have the same shape (specifically, a rectangular shape when viewed from above), and their length (width) along the longitudinal direction of the antenna 2 is, for example, greater than 5 mm and less than 30 mm, but is not limited to this.

[0053] More specifically, the slit plate 6 is manufactured by rolling (e.g., cold rolling or hot rolling) a metal material such as one metal selected from the group consisting of Cu, Al, Zn, Ni, Sn, Si, Ti, Fe, Cr, Nb, C, Mo, W, or Co, or an alloy thereof (e.g., a stainless steel alloy, an aluminum alloy, etc.), and has a thickness of approximately 5 mm. However, the manufacturing method and thickness are not limited to these and may be appropriately modified according to specifications.

[0054] The slit plate 6 is larger than the opening 1x of the vacuum container when viewed from above, and blocks the opening 1x while being supported by the upper wall 1a. A sealing member S such as an O-ring or a gasket is interposed between the slit plate 6 and the upper wall 1a (see FIG. Figure 1 ), which are vacuum sealed.

[0055] The dielectric plate 7 is provided on an outer surface 61 of the slit plate 6 facing the outside of the vacuum vessel 1 (the back surface of the inner surface facing the inside of the vacuum vessel 1 ) to block the slit opening 6 x of the slit plate 6 .

[0056] The dielectric plate 7 is entirely composed of a dielectric material and is flat in shape. Examples include ceramics such as alumina, silicon carbide, and silicon nitride; inorganic materials such as quartz glass and alkali-free glass; and resin materials such as fluororesins (e.g., Teflon). To reduce dielectric loss, the material constituting the dielectric plate 7 preferably has a dielectric loss tangent of 0.01 or less, and more preferably 0.005 or less.

[0057] Here, the thickness of the dielectric plate 7 is smaller than that of the slit plate 6, but this is not limiting. The dielectric plate 7 can be made thinner as long as it has sufficient strength to withstand the differential pressure between the inside and outside of the vacuum vessel 1, which is applied through the slit openings 6x when the vacuum vessel 1 is evacuated. The thickness can be appropriately set based on specifications such as the number and length of the slit openings 6x. However, from the perspective of shortening the distance between the antenna 2 and the vacuum vessel 1, a thinner thickness is preferred.

[0058] With the above configuration, the slit plate 6 and the dielectric plate 7 function as a magnetic field transmission window W that transmits the magnetic field generated by the antenna 2. Specifically, when a high frequency is applied to the antenna 2 from the high-frequency power supply 3, the high-frequency magnetic field generated by the antenna 2 passes through the magnetic field transmission window W including the slit plate 6 and the dielectric plate 7 and is formed (supplied) into the vacuum chamber 1. This generates an induced electric field in the space within the vacuum chamber 1, generating an inductively coupled plasma P.

[0059] Furthermore, the mask member 8 is provided on the inward surface 62 of the slit plate 6 facing the inside of the vacuum container 1 so as to cover the slit opening 6 x of the slit plate 6 .

[0060] Specifically, if Figures 2 to 6As shown, the mask member 8 is provided in an elongated strip shape, extending from one end 6x1 to the other end 6x2 in the longitudinal direction of the slit opening 6x. In this embodiment, the mask member 8 is in the shape of a rectangular flat plate having a longitudinal direction intersecting the antenna 2. More specifically, the length of the mask member 8 in the longitudinal direction is longer than the length of the slit opening 6x in the longitudinal direction, and the length (width) of the mask member 8 along the longitudinal direction of the antenna 2 is approximately the same as the width of the slit opening 6x along the longitudinal direction of the antenna 2.

[0061] Furthermore, when viewed in the thickness direction of the slit plate 6, the mask member 8 is disposed parallel to the slit opening 6x and covers substantially the entire slit opening 6x. Alternatively, the mask member 8 may be formed so as to cover only a portion of the slit opening 6x. Furthermore, from the perspective of improving the transmittance of the magnetic field, the narrower the width of the mask member 8, the more preferable. For example, it is preferably 10 mm or less, and more preferably 5 mm or less.

[0062] Furthermore, the plurality of masking members 8 are arranged parallel to one another when viewed in the longitudinal direction of the antenna 2. Here, each masking member 8 is arranged so as to intersect (specifically, orthogonally intersect) the antenna 2 and has the same flat plate shape. Furthermore, when viewed in the thickness direction of the slit plate 6, each masking member 8 is arranged parallel to each slit opening 6x, and each masking member 8 covers substantially the entirety of each slit opening 6x.

[0063] Furthermore, the mask member 8 is made of a metal material such as a heavy metal with a low thermal expansion coefficient, such as Mo or W, or an alloy thereof. The thickness of the mask member 8 is preferably smaller than that of the slit plate 6, for example, approximately 5 mm or less. However, the thickness of the mask member 8 is not limited to this and can be appropriately changed according to specifications.

[0064] The fixing mechanism 9 positions and fixes each mask member 8 in such a manner that each mask member 8 covers each slit opening 6x. Figures 2 to 6 As shown, the fixing mechanism 9 includes an engaging portion 91 formed on the slit plate 6 and engaging with an end portion in the longitudinal direction of the mask member 8 , and a pressing member 92 for pressing the mask member 8 toward the slit plate 6 .

[0065] The interlocking portion 91 is formed on the inward surface 62 of the slit plate 6 and is arranged corresponding to the two end portions 6x1 and 6x2 of the slit opening 6x. In this embodiment, the interlocking portion 91 includes a recessed portion forming a portion of a rectangular parallelepiped, and the recessed portion constituting the interlocking portion 91 has a longitudinal direction along the long side of the antenna 2. Specifically, the length of the interlocking portion 91 in the longitudinal direction is approximately the same as the length (width) of the mask member 8 along the long side of the antenna 2. In addition, one side of the longitudinal direction of the recessed portion is approximately consistent with the inner side of the vacuum container 1 at the two end portions 6x1 and 6x2 of the slit opening 6x. Furthermore, multiple interlocking portions 91 are arranged along the long side of the antenna 2 and are arranged parallel to each other and spaced apart by the length (width) of the beam-shaped region 6z along the long side of the antenna 2.

[0066] Furthermore, in this embodiment, a mounting surface 91a for mounting the mask member 8 is formed on the fitting portion 91. Specifically, by positioning the mounting surface 91a closer to the inside of the vacuum vessel 1 than the inward-facing surface 62, each mask member 8 covers each slit opening 6x from the inside of the vacuum vessel 1, separated by a gap G. This reduces the induced current generated along the antenna 2 in the mask member 8 and the slit plate, effectively suppressing a decrease in the transmittance of the high-frequency magnetic field. Furthermore, the gap G between the outer surface of the mask member 8 and the inward-facing surface 62 of the slit plate 6 is preferably set to a value of 5 mm or less.

[0067] More specifically, the fitting portion 91 is made of the same material as the slit plate 6 and is manufactured by rolling (e.g., cold rolling or hot rolling) a metal material such as one metal selected from the group consisting of Cu, Al, Zn, Ni, Sn, Si, Ti, Fe, Cr, Nb, C, Mo, W, or Co, or an alloy thereof (e.g., a stainless steel alloy or an aluminum alloy). However, the fitting portion 91 does not necessarily have to be made of the same material as the slit plate 6.

[0068] The pressing member 92 is elongated along the longitudinal direction of the antenna 2 and engages with the engaging portion 91 while pressing the mask member 8. Specifically, the pressing member 92 has a plurality of protrusions 921 formed along the longitudinal direction of the pressing member 92, which engage with the recessed portion forming the engaging portion 91. These protrusions 921 are arranged parallel to each other and spaced apart by the length (width) of the beam-shaped region 6z along the longitudinal direction of the antenna 2. In this embodiment, the protrusions 921 are rectangular parallelepiped-shaped, extending along the longitudinal direction of the antenna 2. The length of the protrusions 921 along the longitudinal direction of the antenna 2 and the length in the direction intersecting the antenna 2 are approximately the same as the length of the recessed portion of the engaging portion 91 in the longitudinal and transverse directions, respectively.

[0069] Furthermore, in the above embodiment, a flow path 6c for circulating a cooling medium such as water is formed (or provided) in the slit plate 6. The flow path 6c is formed near the fixing mechanism 9 along the longitudinal direction of the antenna 2. Here, the flow path 6c is formed so as to be located directly above the fixing mechanism 9 along the thickness direction of the slit plate 6.

[0070] <Effects of this embodiment>

[0071] According to the plasma processing apparatus 100 of this embodiment, as compared to a mask plate in which the slit plate 6 is covered by a flat plate, the size of each mask member 8 is reduced because the mask members 8 are provided at each slit opening 6x. Consequently, the mask members 8 are less likely to warp, and the thickness of the mask members 8 can be reduced. As a result, a decrease in the transmittance of the high-frequency magnetic field generated by the antenna 2 can be suppressed.

[0072] In addition, each mask member 8 is provided for each slit opening 6x, and the mask member 8 does not need to be cut to form a slit, so heavy metals such as Mo or W with a small thermal expansion coefficient can be used as the material of the mask member 8, thereby suppressing the deformation of the mask member 8 caused by heating.

[0073] Furthermore, according to the plasma processing apparatus 100 of this embodiment, the mask member 8 is positioned by the engaging portion 91. Therefore, when the pressing member 92 is pressing the mask member 8, displacement of the mask member 8 can be suppressed. Furthermore, since the mask member 8 is provided along the longitudinal direction of the slit opening 6x, the mask member 8 can be fixed corresponding to the slit opening 6x, thereby preventing conductive flying objects from adhering to the dielectric plate and causing contamination.

[0074] <Other Modified Embodiments>

[0075] In addition, the present invention is not limited to the above-described embodiments.

[0076] In the present embodiment, the mask member 8 is in the shape of a rectangular flat plate, but the mask member 8 may be in another long shape such as a column.

[0077] In the present embodiment, the fitting portion 91 is formed on the slit plate 6 , but the fitting portion 91 may be formed on the pressing member 92 .

[0078] In another embodiment of the plasma processing apparatus 100, as Figures 7 to 9As shown, a plurality of mask members 8 may be provided for each slit opening 6x, and the plurality of mask members 8 provided for the slit opening 6x may be staggered and cover the slit opening 6x. In this case, the mask members 8 are staggered along the long side direction of the antenna 2 by the fixing mechanism 9, and are also separated from each other by a gap G' when viewed from the thickness direction of the slit plate 6. In addition, the mask members 8 may or may not overlap with each other when viewed from the long side direction of the antenna 2 or the thickness direction of the slit plate 6. In addition, the size of the gap G' between the mask members 8 is not particularly limited. Furthermore, in Figures 7 to 9 In the embodiment, two mask members 8 are provided for each slit opening 6 x , but the number of mask members 8 provided for each slit opening 6 x may be three or more.

[0079] With this structure, the width of each mask member 8 along the longitudinal direction of the antenna 2 is reduced compared to a case where the slit opening 6x is covered by a single mask member 8. This reduces the induced current generated in each mask member 8, further suppressing a decrease in the transmittance of the high-frequency magnetic field. Furthermore, since multiple mask members 8 are arranged with gaps G' spaced apart from each other, any unevenness in the plasma density that could be generated along the antenna 2 due to contact between the multiple mask members 8 can be suppressed.

[0080] In addition, in another embodiment of the plasma processing apparatus 100, as shown in FIG. Figure 10 as well as Figure 11 As shown, a plurality of mask members 8 may be provided for each slit opening 6x along the longitudinal direction of the antenna 2, each of the mask members 8 being strip-shaped and having different lengths in the longitudinal direction. In the thickness direction of the slit plate 6, the mask members 8' are arranged longer in the longitudinal direction as they move toward the interior of the vacuum container 1. In this case, the fitting portion 91 may further include a plurality of recesses provided along the longitudinal direction of the antenna 2 and respectively fitted with the ends of the mask members 8. The fitting portion 91 is configured such that the ends of the mask members 8' that are longer in the longitudinal direction are clamped by a connecting wall w1 formed by connecting adjacent portions of the plurality of recesses and an opposing wall w2 provided opposite the connecting wall w1.

[0081] In the embodiment described above, the fitting portion 91 includes a first recess 911, which fits with the shorter mask member 8 in the longitudinal direction, and a second recess 912, which fits with the longer mask member 8' in the longitudinal direction. The first recess 911 is located closer to the ends 6x1 and 6x2 of the slit opening 6x than the second recess 912. When viewed in the thickness direction of the slit plate 6, the mounting surface of the first recess 911, on which the mask member 8 is mounted, is formed between the inward surface 62 of the slit plate 6 and the mounting surface of the second recess 912, on which the mask member 8' is mounted. Furthermore, the adjacent arrangement of the first recess 911 and the second recess 912 forms a connecting wall w1. The second recess 912 forms an opposing wall w2, which opposes the connecting wall w1. The connecting wall w1 and the opposing wall w2 are arranged parallel to each other and spaced apart by approximately the same length as the lateral length of the mask member 8'.

[0082] With this structure, when each mask member 8 is mounted on the slit plate 6, the mask members 8 and 8' are fixed by the connecting wall w1 and the facing wall w2, thereby preventing the mask members 8 and 8' from shifting in the longitudinal direction of the antenna 2. In particular, when a mask member 8' that is longer in the longitudinal direction is mounted on the slit plate 6, the mask member 8' is prevented from falling off the slit plate 6.

[0083] Furthermore, since the adjacent portions of the first recess 911 and the second recess 912 are connected, the mask members 8, 8' provided for each slit opening 6x are arranged without gaps when viewed from the inside of the vacuum vessel 1. Therefore, when viewed from the inside of the vacuum vessel 1, the mask members 8, 8' provided for each slit opening 6x cover the dielectric plate 7 without gaps, thereby preventing conductive flying objects from adhering to the dielectric plate 7 and causing contamination.

[0084] In addition, in a plasma processing apparatus 100 of another embodiment, a shielding wall SW may be provided in the gap G between the slit plate 6 and the mask member 8, wherein the shielding wall SW shields the charged particles moving along the long side direction of the antenna 2. The shielding wall SW may have a wall surface formed in a manner intersecting (specifically, orthogonal to) the long side direction of the antenna 2. When viewed from the long side direction of the antenna 2, the shielding wall SW may be formed in a manner so as to shield all or part of the gap G. Moreover, a plurality of shielding walls SW may be provided along the long side direction of the antenna 2. The plurality of shielding walls SW are preferably parallel to each other and provided at a certain interval (pitch) along the long side direction of the antenna 2. The interval (pitch) between the plurality of shielding walls SW along the long side direction of the antenna 2 may be equal to or different from the interval between the slit openings 6x of the slit plate 6.

[0085] Specifically, for example Figure 12As shown, a projection 6p may be formed on the inner surface of the beam-shaped region 6z of the slit plate 6, projecting toward the outer surface 81 of the mask member 8 and into the gap G, with the projection 6p constituting the shielding wall SW. Alternatively, a projection may be formed on the outer surface 81 of the mask member 8, projecting toward the inner surface 62 of the slit plate 6 and into the gap G, with the projection constituting the shielding wall SW.

[0086] The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit and scope of the invention.

[0087] Industrial applicability

[0088] According to the present invention, in a plasma processing apparatus in which an antenna is arranged outside a vacuum container and a dielectric plate and a slit plate are overlapped to form a magnetic field transmission window, the thickness of a mask member covering the slit formed in the slit plate can be reduced and a material with a low thermal expansion coefficient can be used for the mask member.

[0089] Explanation of Figure Numbers

[0090] 100: Plasma treatment device

[0091] O: substrate

[0092] P: Inductively coupled plasma

[0093] 2: Antenna

[0094] 3: High frequency power supply

[0095] 6: Slit plate

[0096] 6x: Slit opening

[0097] 7: Dielectric board

[0098] 8: Mask component

[0099] 9: Fixed mechanism

[0100] 91: Chimera Department

[0101] 92: Pressing component

[0102] W: Magnetic field transmission window

[0103] S: Sealing component

Claims

1. A plasma processing apparatus that generates plasma in a vacuum container by passing a high-frequency current through an antenna disposed outside the vacuum container, the plasma processing apparatus comprising: a slit plate for blocking an opening formed in the vacuum container at a position facing the antenna; a dielectric plate for blocking the plurality of slit openings formed in the slit plate from the outside of the vacuum container; a plurality of mask members provided for each of the slit openings and covering the slit openings with gaps therebetween from the inside of the vacuum container; as well as The fixing mechanism fixes the plurality of mask members corresponding to each of the slit openings.

2. The plasma processing apparatus according to claim 1, wherein The slit opening has a rectangular shape having a long side in a direction intersecting the antenna. The mask member is provided from one end to the other end in the longitudinal direction of the slit opening and has an elongated shape. The fixing mechanism comprises: a pressing member that presses the mask member toward the slit plate; and The fitting portion is formed on the pressing member or the slit plate and fits with an end portion in the longitudinal direction of the mask member.

3. The plasma processing apparatus according to claim 1, wherein: The mask member is provided with a plurality of masks for each slit opening. The plurality of mask members provided at the slit opening are arranged with gaps therebetween to cover the slit opening.

4. The plasma processing apparatus according to claim 2, wherein: The mask member is provided in plurality for each of the slit openings along the longitudinal direction of the antenna and has a strip shape with different lengths in the longitudinal direction. In the thickness direction of the slit plate, a mask member is arranged so as to be longer in the longitudinal direction as it goes toward the inner side of the vacuum container. The fitting portion further includes a plurality of recesses, which are provided along the longitudinal direction of the antenna and are respectively fitted with the ends of the mask members. The plurality of mask members provided at the slit openings are sandwiched by a communication wall formed by communicating adjacent portions of the plurality of recesses and facing walls provided at the plurality of recesses facing the communication wall.

5. The plasma processing apparatus according to any one of claims 1 to 4, wherein: A shielding wall is provided in a gap between the slit plate and the mask member, and the shielding wall shields charged particles moving along the longitudinal direction of the antenna.

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