Plasma processing equipment

Abstract

To increase maintainability of a slit plate in a plasma processing apparatus comprising an antenna arranged outside a vacuum vessel and a magnetic-field transmission window formed by superposing a dielectric plate and the slit plate.SOLUTION: A plasma processing apparatus in which a high-frequency current is passed through an antenna provided outside a vacuum vessel forming a processing chamber therein to generate plasma in the processing chamber, comprises: a slit plate provided so as to block an opening formed at a position facing the antenna provided of the vacuum vessel; a dielectric plate provided so as to block slits formed in the slit plate from the outer side of the vacuum vessel. The slit plate comprises an annular frame, and a plurality of beam-like members bridged side-by-side over the frame. The slits are formed from gaps between the plurality of beam-like members.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] A plasma processing apparatus has been conventionally proposed in which a high-frequency current is passed through an antenna, and an inductively coupled plasma (abbreviated as ICP) is generated by an induced electric field generated thereby, and a workpiece such as a substrate is processed using this inductively coupled plasma. As such a plasma processing apparatus, Patent Document 1 discloses a plasma processing apparatus that generates plasma in a vacuum chamber by disposing an antenna outside the vacuum chamber and allowing a high-frequency magnetic field generated from the antenna to penetrate into the vacuum chamber through a magnetic field transmission window provided so as to close an opening in the side wall of the vacuum chamber.

[0003] The plasma processing apparatus of this Patent Document 1 includes a metal slit plate that closes an opening in the vacuum chamber, and a dielectric plate that closes a slit formed in the slit plate from the outside of the vacuum chamber. In this plasma processing apparatus, since the metal slit plate and the dielectric plate superimposed on the slit plate are made to function as a magnetic field transmission window, the thickness of the magnetic field transmission window can be made smaller than in the case where only the dielectric plate functions as a magnetic field transmission window. As a result, the distance from the antenna to the inside of the vacuum chamber can be shortened, and the high-frequency magnetic field generated from the antenna can be efficiently supplied into the vacuum chamber.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the plasma processing apparatus configuration of Patent Document 1 described above, deposits from plasma generated near the slits and deposits from particles that wrap around due to sputtering etc. adhere to the slit plate, requiring periodic cleaning of the slit plate. However, this requires cleaning each of the multiple slit holes formed in the slit plate one by one, which is time-consuming.

[0006] The present invention was made to solve the aforementioned problems, and its main objective is to improve the maintainability of the slit plate in a plasma processing apparatus in which an antenna is placed outside the vacuum vessel and a magnetic field transmission window is constructed by stacking a dielectric plate and a slit plate. [Means for solving the problem]

[0007] In other words, the plasma processing apparatus according to the present invention generates plasma in the processing chamber by passing a high-frequency current through an antenna provided outside a vacuum vessel forming a processing chamber, and comprises a slit plate provided to close an opening formed in the vacuum vessel facing the antenna, and a dielectric plate that closes the slit formed in the slit plate from the outside of the vacuum vessel, wherein the slit plate comprises an annular frame and a plurality of beam-shaped members arranged side by side across the frame, and the slit is formed by the gaps between the plurality of beam-shaped members. [Effects of the Invention]

[0008] According to the present invention configured in this way, in a plasma processing apparatus in which an antenna is placed outside a vacuum vessel and a magnetic field transmission window is formed by stacking a dielectric plate and a slit plate, the maintainability of the slit plate can be improved. [Brief explanation of the drawing]

[0009] [Figure 1] A schematic longitudinal cross-sectional view showing the configuration of a plasma processing apparatus according to one embodiment. [Figure 2] A schematic cross-sectional view showing the configuration of the plasma processing apparatus of the same embodiment. [Figure 3] This diagram schematically shows the configuration of the slit plate in the same embodiment, and is a plan view as seen from the antenna side. [Figure 4] This is a schematic vertical cross-sectional view showing the configuration of the slit plate of the same embodiment, with (a) a vertical cross-sectional view showing the state with the beam-like member removed and (b) a state with the beam-like member, dielectric plate and antenna installed. [Figure 5] This diagram schematically shows the configuration of a slit plate in another embodiment, and is a plan view as seen from the antenna side. [Figure 6] These are schematic longitudinal cross-sectional views illustrating the configuration of a slit plate in another embodiment, with (a) a schematic longitudinal cross-sectional view showing the section along line A-A' in Figure 5 and (b) a schematic longitudinal cross-sectional view showing the section along line B-B' in Figure 5. [Figure 7] This is a schematic cross-sectional view showing the configuration of a slit plate in another embodiment. [Figure 8] This is a schematic cross-sectional view showing the configuration of a slit plate in another embodiment. [Figure 9] This is a schematic longitudinal cross-sectional view showing the configuration of a slit plate in another embodiment, with (a) showing the configuration near the first beam-like member and (b) showing the configuration near the second beam-like member. [Figure 10] This is a schematic cross-sectional view showing the configuration near the slit plate in another embodiment. [Figure 11] This is a schematic longitudinal cross-sectional view showing the configuration near the slit plate in another embodiment. [Figure 12] This is a schematic longitudinal cross-sectional view showing the configuration near the slit plate in another embodiment. [Modes for carrying out the invention]

[0010] An embodiment of the plasma processing apparatus according to the present invention will be described below with reference to the drawings.

[0011] <Device configuration> The plasma processing apparatus 100 of this embodiment performs processing on a substrate O using inductively coupled plasma P. Here, the substrate O is, for example, a substrate for a flat panel display (FPD) such as a liquid crystal display or an organic EL display, a flexible substrate for a flexible display, or the like. Further, the processing performed on the substrate O is, for example, film formation by plasma CVD method, etching, ashing, sputtering, or the like.

[0012] In addition, when the plasma processing apparatus 100 forms a film by the plasma CVD method, it is also called a plasma CVD apparatus, when performing etching, it is called a plasma etching apparatus, when performing ashing, it is called a plasma ashing apparatus, and when performing sputtering, it is called a plasma sputtering apparatus.

[0013] Specifically, as shown in FIGS. 1 and 2, the plasma processing apparatus 100 includes a vacuum vessel 1 that forms a processing chamber evacuated and into which gas is introduced, an antenna 2 provided outside the vacuum vessel 1, and a high-frequency power supply 3 that applies a high-frequency signal to the antenna 2. In such a configuration, by applying a high-frequency signal from the high-frequency power supply 3 to the antenna 2, a high-frequency current IR flows through the antenna 2, an inductive electric field is generated in the vacuum vessel 1, and inductively coupled plasma P is generated.

[0014] The vacuum vessel 1 is, for example, a metal container, and an opening 1x penetrating in the thickness direction is formed in its wall (here, the upper wall 1a). The vacuum vessel 1 is electrically grounded here, and the internal processing chamber is evacuated by a vacuum evacuation device 4.

[0015] In addition, gas is introduced into the vacuum chamber 1 via, for example, a flow regulator (not shown) or one or more gas inlets 11 provided in the vacuum chamber 1. The gas may be selected according to the processing content to be applied to the substrate O. For example, when forming a film on the substrate by plasma CVD method, the gas is a source gas or a gas diluted with a dilution gas (e.g., H2). More specifically, when the source gas is SiH4, a Si film can be formed; when it is SiH4 + NH3, a SiN film can be formed; when it is SiH4 + O2, a SiO2 film can be formed; and when it is SiF4 + N2, a SiN:F film (fluorinated silicon nitride film) can be formed on the substrate, respectively.

[0016] Inside this vacuum chamber 1, a substrate holder 5 for holding the substrate O is provided. As in this example, a bias voltage may be applied from a bias power supply 6 to the substrate holder 5. The bias voltage is, for example, a negative DC voltage, a negative bias voltage, etc., but is not limited to this. By such a bias voltage, for example, the energy when positive ions in the plasma P are incident on the substrate O can be controlled, and the crystallinity of the film formed on the surface of the substrate O can be controlled, etc. A heater 51 for heating the substrate O may be provided inside the substrate holder 5.

[0017] As shown in FIGS. 1 and 2, the antenna 2 is arranged so as to face an opening 1x formed in the vacuum chamber 1. The number of antennas 2 is not limited to one, and a plurality of antennas 2 may be provided.

[0018] As shown in FIG. 2, for the antenna 2, a power feeding end portion 2a which is one end portion thereof is connected to a high-frequency power supply 3 via a matching circuit 31, and a terminating end portion 2b which is the other end portion is directly grounded. The terminating end portion 2b may be grounded via a capacitor or a coil, etc.

[0019] The high-frequency power supply 3 can pass a high-frequency current IR through the antenna 2 via the matching circuit 31. The frequency of the high frequency is, for example, a common 13.56 MHz, but is not limited to this and may be appropriately changed.

[0020] This plasma processing apparatus 100 further includes a slit plate 7 that closes an opening 1x formed in the wall (upper wall 1a) of the vacuum vessel 1 from the outside of the vacuum vessel 1, and a dielectric plate 8 that closes a slit 7x formed in the slit plate 7 from the outside of the vacuum vessel 1.

[0021] The slit plate 7 allows the high-frequency magnetic field generated from the antenna 2 to pass through into the vacuum container 1, while preventing the electric field from entering the vacuum container 1 from the outside. Specifically, as shown in Figure 3, the slit plate 7 is a flat rectangular plate with multiple slits 7x extending through its thickness arranged at equal intervals along the longitudinal direction of the antenna 2. The slit plate 7 preferably has higher mechanical strength than the dielectric plate 8, which will be described later, and preferably has a larger thickness than the dielectric plate 8. The multiple slits 7x are parallel to each other when viewed from the thickness direction and are formed to intersect (specifically, perpendicular to) the antenna 2. All of the multiple slits 7x are the same shape (specifically rectangular in plan view), and their length (width) along the longitudinal direction of the antenna 2 is, for example, 5 mm to 30 mm, but is not limited to this.

[0022] The slit plate 7 is larger than the opening 1x of the vacuum vessel in a plan view and is supported by the upper wall 1a, thereby blocking the opening 1x. A sealing member S1 (see Figures 1 and 2), such as an O-ring or gasket, is interposed between the slit plate 7 and the upper wall 1a, and the space between them is vacuum-sealed.

[0023] The dielectric plate 8 is provided on the outward-facing surface 7a of the slit plate 7 (the back surface of the inward-facing surface facing the inside of the vacuum container 1) and closes the slit 7x of the slit plate 7.

[0024] The dielectric plate 8 is a flat plate composed entirely of a dielectric material, such as ceramics like alumina, silicon carbide, or silicon nitride; inorganic materials like quartz glass or alkali-free glass; or resin materials like fluororesin (e.g., Teflon). From the viewpoint of reducing dielectric loss, the materials constituting the dielectric plate 8 are preferably those with a dielectric loss tangent of 0.01 or less, and more preferably those with a dielectric loss tangent of 0.005 or less.

[0025] Here, the thickness of the dielectric plate 8 is made smaller than the thickness of the slit plate 7, but this is not limited to this. For example, it is sufficient to have enough strength to withstand the differential pressure inside and outside the vacuum container 1 when the vacuum container 1 is evacuated, and the number and length of the slits 7x can be set as appropriate according to the specifications. However, a thinner material is preferable from the viewpoint of shortening the distance between the antenna 2 and the vacuum container 1. A sealing member S2 such as an O-ring or gasket is interposed between the dielectric plate 8 and the slit plate 7, and the space between them is vacuum-sealed.

[0026] In this configuration, the slit plate 7 and the dielectric plate 8 function as a magnetic field transmission window W that allows the magnetic field generated from the antenna 2 to pass through. That is, when a high frequency is applied to the antenna 2 from the high-frequency power supply 3, the high-frequency magnetic field generated from the antenna 2 passes through the magnetic field transmission window W consisting of the slit plate 7 and the dielectric plate 8 and is formed (supplied) into the vacuum container 1. As a result, an induced electric field is generated in the space inside the vacuum container 1, and an inductively coupled plasma P is generated.

[0027] However, in the plasma processing apparatus 100 of this embodiment, as shown in Figures 1-4, the slit plate 7 comprises an annular frame 71 and a plurality of beam-shaped members 72 arranged side by side across the frame 71, and the gaps between the plurality of beam-shaped members 72 form the slit 7X. The frame 71 and the plurality of beam-shaped members 72 that constitute the slit plate 7 are both electrically connected to the vacuum vessel 1 and are both at ground potential.

[0028] The frame 71 is a plate-shaped material made of a metallic material such as one metal or an alloy thereof (e.g., stainless steel alloy, aluminum alloy, etc.) selected from the group including Cu, Al, Zn, Ni, Sn, Si, Ti, Fe, Cr, Nb, C, Mo, W, or Co. When viewed from the antenna 2 side in plan view, the frame 71 has a shape that frames the rectangular opening 71a, and both its outer edge 71o and inner edge 71i are rectangular. Multiple grooves 71g are formed in pairs on the inner edge 71i of the frame 71, flanking the opening 71a. Specifically, these multiple pairs of grooves 71g are formed by cutting out a pair of opposing sides parallel to the longitudinal direction of the antenna 2, and are arranged at equal intervals along the longitudinal direction of the antenna 2. In this embodiment, all of the multiple grooves 71g have the same cross-sectional shape (here rectangular) and are formed to be approximately the same depth.

[0029] The beam-shaped member 72 is elongated and extends in a direction perpendicular to the antenna 2, and in this embodiment, it has substantially the same cross-sectional shape along its longitudinal direction. Both ends 72a of the beam-shaped member 72 along its longitudinal direction have substantially the same cross-sectional shape as the groove 71g of the frame 71, and by fitting both ends 72a into the groove 71g of the frame 71, multiple beam-shaped members 72 are spanned across the frame 71 at the same height. All of the multiple beam-shaped members 72 have the same shape with the same length and width, and are detachably attached to the frame 71 at substantially equal intervals along the longitudinal direction of the antenna 2. As shown in Figure 4, the height dimension of the beam-shaped member 72 is substantially the same as or smaller than the depth dimension of the groove 71g of the frame 71.

[0030] The beam-like member 72 is made of a metallic material such as one metal selected from the group including Cu, Al, Zn, Ni, Sn, Si, Ti, Fe, Cr, Nb, C, Mo, W, or Co, or an alloy thereof (e.g., stainless steel alloy, aluminum alloy, etc.). For example, it is made of a material with a higher Young's modulus than the frame 71, such as SUS.

[0031] <Effects of this embodiment> In the plasma processing apparatus 100 of this embodiment, configured as described above, the slit plate 7 is composed of a frame 71 and a plurality of beam-shaped members 72 spanning the frame 71, and the slits 7x are formed by the gaps between the beam-shaped members 72. Therefore, during cleaning, the beam-shaped members 72 that are dirtier due to the accumulation of deposits, etc., can be removed from the frame 71 and replaced, thus eliminating the need to clean each of the multiple slits 7x individually and simplifying maintenance. Furthermore, by configuring the slit plate 7 as two types of components, the frame 71 and the beam-shaped members 72, the processing of each component can be simplified compared to forming the slit plate 7 by processing a single metal plate. As a result, there is no need to use materials that are easy to cut, such as aluminum, and it is possible to use metal materials with higher strength, such as SUS, and the slit plate 7 can be made thinner. This allows the distance from the antenna to the vacuum vessel to be shortened even further, and the high-frequency magnetic field generated from the antenna can be supplied to the vacuum vessel more efficiently.

[0032] <Other modified embodiments> However, the present invention is not limited to the embodiments described above.

[0033] For example, in the above embodiment, the multiple beam-like members 72 were attached to the frame 71 so that they were all at the same height, but the embodiment is not limited to this. In other embodiments, the slit plate 7 has multiple first beam-like members 721 and multiple second beam-like members 722 that are spanned across the frame 71 at different heights, as shown in Figures 5, 6, and 7, and the first beam-like members 721 and the second beam-like members 722 may be arranged alternately along the longitudinal direction of the antenna 2. Specifically in this embodiment, first grooves and second grooves 712g of different depths are formed alternately in the frame 71 along the longitudinal direction of the antenna 2, and the first beam-like members 721 and the second beam-like members 722 are spanned across these first grooves 711g and second grooves 712g, respectively. In the configuration shown in Figures 5-7, the first beam-like member 721 is positioned closer to the antenna 2 than the second beam-like member 722 (i.e., the second groove 712g is deeper than the first groove 711g).

[0034] In this embodiment, the first beam-shaped member 721 and the second beam-shaped member 722 are attached to the frame 71 so as not to come into contact with each other. Specifically, the upper surface (the surface on the antenna 2 side) of the second beam-shaped member 722, which is fitted into the second groove 712g, is lower than the position of the bottom surface of the first groove 711g, and the bottom surface (the surface on the processing chamber side) of the first beam-shaped member 721 is higher than the upper surface of the second beam-shaped member 722.

[0035] In this embodiment, in a plan view from the antenna 2 side, the first beam-like member 721 and the second beam-like member 722 are arranged without gaps and without overlapping. Specifically, in the longitudinal direction of the antenna 2, the gap dimension between the first beam-like members 721 is equal to the width dimension of the second beam-like member 722, and the gap dimension between the second beam-like members 722 is equal to the width dimension of the first beam-like member 721. Of course, in a plan view from the antenna 2 side, there may be a gap between the first beam-like member 721 and the second beam-like member 722, and they may also be arranged to overlap.

[0036] Furthermore, when the antenna has a first beam-like member 721 and a second beam-like member 722, as shown in Figures 8 and 9, the slit plate 7 may have a shielding wall 73 between the first beam-like member 721 and the second beam-like member 722 to shield charged particles moving along the longitudinal direction of the antenna 2. This shielding wall 73 may have a wall surface 73a formed to intersect (specifically, perpendicular to) the longitudinal direction of the antenna 2. This wall surface 73a is elongated in a direction intersecting the antenna 2 and preferably has approximately the same length as the opening 71a of the frame 71. For example, this shielding wall 73 may be composed of projections that protrude from one of the beam-like members, the first beam-like member 721 and the second beam-like member 722, toward the gap between the other beam-like member. The slit plate 7 may have a plurality of shielding walls 73 along the longitudinal direction of the antenna 2.

[0037] Furthermore, although the cross-sectional shape of the groove 71g was rectangular in the above embodiment, it is not limited to this. In other embodiments, as shown in Figure 10, the cross-sectional shape of the groove 71g may be V-shaped or partially circular. Also, the cross-sectional shape of the beam-like member 72 may be triangular or circular to match the cross-sectional shape of the groove 71g.

[0038] Furthermore, the beam-shaped member 72 may have film-adhesion-inhibiting protrusions 74 projecting toward the processing chamber in areas other than the ends 72a that are placed over the groove 71g. These film-adhesion-inhibiting protrusions 74 are for preventing deposits from adhering to the groove 71g over which the beam-shaped member 72 is placed, and when viewed from the longitudinal direction of the antenna 2, they face the inner circumferential surface 71s of the frame 71 and have a covering surface 74a that covers the inner circumferential surface 71s. The film-adhesion-inhibiting protrusions may be provided only near the ends 72a of the beam-shaped member 72, as shown in Figure 11, or they may be formed over the entire opening 71a, as shown in Figure 12.

[0039] Furthermore, it goes without saying that the present invention is not limited to the embodiments described above, and various modifications are possible without departing from its spirit.

[0040] Furthermore, the disclosures herein may include the following embodiments 1-7.

[0041] (Aspect 1) A plasma processing apparatus that generates plasma in a processing chamber by passing a high-frequency current through an antenna provided on the outside of a vacuum vessel forming a processing chamber, comprising: a slit plate provided to close an opening formed in the vacuum vessel at a position facing the antenna; and a dielectric plate that closes a slit formed in the slit plate from the outside of the vacuum vessel, wherein the slit plate comprises an annular frame and a plurality of beam-shaped members arranged and spanned across the frame, and the slit is formed by the gaps between the plurality of beam-shaped members. In this configuration, the slit plate is composed of a frame and multiple beam-like members spanning the frame, with slits formed by the gaps between the beam-like members. Therefore, during cleaning, only the more soiled beam-like members, such as those with accumulated deposits, need to be removed from the frame and replaced, eliminating the need to clean each slit individually and simplifying maintenance. Furthermore, by constructing the slit plate from two types of components—the frame and the beam-like members—the processing of individual components can be simplified compared to forming the slit plate from a single metal plate. As a result, there is no need to use materials that are easy to cut, such as aluminum, and it becomes possible to use metal materials with higher strength, such as SUS, allowing for a thinner slit plate. This shortens the distance from the antenna to the vacuum vessel, enabling efficient supply of the high-frequency magnetic field generated by the antenna into the vacuum vessel.

[0042] (Aspect 2) The plasma processing apparatus according to aspect 1, wherein a plurality of grooves forming a pair on the inner peripheral edge of the frame body are formed on either side of the opening, and both ends of the beam-shaped member are hung in each of the paired grooves. With this configuration, the beam-shaped member can be attached to the frame by placing it in the groove, thus preventing misalignment of the beam-shaped member, and also making it easy to attach and detach the beam-shaped member.

[0043] (Aspect 3) The plasma processing apparatus according to aspect 2, wherein the cross-sectional shape of the groove is V-shaped or partially circular. When the groove has a rectangular cross-section, there is a possibility that the beam-like member may be misaligned within the groove due to counterboring. However, by making the groove's cross-sectional shape V-shaped or partially circular, this problem of misalignment can be resolved.

[0044] (Aspect 4) The plasma processing apparatus according to aspect 2 or 3, wherein the beam-shaped member has projections that protrude toward the processing chamber in areas other than the ends that are placed over the groove. With this configuration, the protrusions that extend towards the processing chamber function as covers that suppress the adhesion of deposits to the inner surface of the frame, thereby reducing the amount of deposits adhering to the frame and further improving maintainability.

[0045] (Aspect 5) The plasma processing apparatus according to any of aspects 1-4, wherein the slit plate comprises a first beam-like member and a second beam-like member that are spanned across the frame at different heights in the plate thickness direction, and the first beam-like member and the second beam-like member are arranged alternately along the longitudinal direction of the antenna. With this configuration, in a plan view, the first beam-like member and the second beam-like member are arranged alternately along the longitudinal direction of the antenna, so that the dielectric plate is hidden when viewed from inside the vacuum vessel. This prevents conductive flying objects from adhering to and contaminating the dielectric plate. As a result, the surface of the dielectric plate does not become conductive, the decrease in the transmittance of high-frequency magnetic fields is suppressed, and heat generation due to induced current flowing on the surface of the dielectric plate is also prevented. Furthermore, since the second beam-shaped member is positioned between the first beam-shaped members, the dielectric plate exposed through the slit between the first beam-shaped members is not directly exposed to plasma or the workpiece, thus suppressing the temperature rise of the dielectric plate due to radiation and preventing damage. Furthermore, because the first beam-like member and the second beam-like member are at different heights, the induced current generated in the slit plate along the antenna can be reduced, and the decrease in the transmittance of the high-frequency magnetic field can be efficiently suppressed.

[0046] (Aspect 6) The plasma processing apparatus according to aspect 5, wherein the gap dimension between the first beam-like members and the width dimension of the second beam-like member are substantially the same in the longitudinal direction of the antenna. In this way, the dielectric plate is completely hidden when viewed from the inside of the vacuum chamber, which further prevents conductive flying objects from adhering to and contaminating the dielectric plate.

[0047] (Aspect 7) The plasma processing apparatus according to aspect 6, wherein the slit plate has a shielding wall between the first beam-shaped member and the second beam-shaped member for shielding charged particles moving along the longitudinal direction of the antenna. In this way, the movement of charged particles along the longitudinal direction of the antenna within the gap between the first beam-like member and the second beam-like member can be suppressed by the shielding wall, thereby preventing the generation of discharge within the gap. [Explanation of Symbols]

[0048] 100... Plasma processing equipment P ···Inductively coupled plasma 2...Vacuum container 3... Antenna 7 ···Slit plate 71...Frame body 71i...Inner periphery 72 ···Beam-like member 7x ···Slit 8. Dielectric Plate

Claims

1. A plasma processing apparatus that generates plasma inside a processing chamber by passing a high-frequency current through an antenna provided outside a vacuum vessel forming a processing chamber, A slit plate is provided to close an opening formed in the vacuum vessel at a position facing the antenna, The vacuum container comprises a dielectric plate that closes the slit formed in the slit plate from the outside, A plasma processing apparatus comprising a slit plate having an annular frame and a plurality of beam-like members arranged side by side across the frame, wherein the slit is formed by the gaps between the plurality of beam-like members.

2. Multiple grooves are formed in pairs on the inner peripheral edge of the frame, flanking the opening. The plasma processing apparatus according to claim 1, wherein both ends of the beam-shaped member are hooked onto each of the paired grooves.

3. The plasma processing apparatus according to claim 2, wherein the cross-sectional shape of the groove is V-shaped or partially circular.

4. The plasma processing apparatus according to claim 2, wherein the beam-shaped member has projections that protrude toward the processing chamber in areas other than the ends that are placed in the groove.

5. The slit plate comprises a first beam-like member and a second beam-like member that are spanned across the frame at different heights in the thickness direction of the plate, The plasma processing apparatus according to claim 1, wherein the first beam-shaped member and the second beam-shaped member are arranged alternately along the longitudinal direction of the antenna.

6. The plasma processing apparatus according to claim 5, wherein, in the longitudinal direction of the antenna, the gap dimension between the first beam-like members and the width dimension of the second beam-like member are substantially the same.

7. The plasma processing apparatus according to claim 6, wherein the slit plate has a shielding wall between the first beam-shaped member and the second beam-shaped member for shielding charged particles moving along the longitudinal direction of the antenna.

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