JP5271586B2 - Plasma processing vessel and plasma processing apparatus - Google Patents

Description

  The present invention relates to a plasma processing container for storing a target object when plasma processing is performed on the target object such as a glass substrate for a flat panel display (FPD), and a plasma processing apparatus including the plasma processing container. .

  In an FPD manufacturing process typified by a liquid crystal display (LCD), various processes such as etching and film formation are performed on an object to be processed such as a glass substrate under vacuum. In order to perform the processing using plasma, a plasma processing apparatus including a plasma processing container that can be evacuated is used.

  In the plasma processing apparatus, the inner surface of the metal plasma processing container may be damaged by the action of plasma or corrosive gas. For this reason, for example, the body of a plasma processing vessel made of aluminum is subjected to anodizing treatment (alumite treatment) to improve corrosion resistance. The alumite treatment is usually carried out by immersing the plasma treatment container or the component to be treated in an electrolytic solution containing sulfuric acid or oxalic acid.

  In order to prevent damage to the plasma processing container, a protective member (liner) is also provided on the inner wall surface of the plasma processing container. For example, Patent Document 1 proposes to dispose a detachable liner along the inner wall surface of the transfer port formed in the plasma processing container. On the surface of the liner, an oxide film by alumite treatment and a sprayed coating having plasma erosion resistance are formed to improve durability against plasma and corrosive gas. However, since plasma and corrosive gas may circulate from the end of the liner attached to the inner surface of the plasma processing container to the back side (gap with the plasma processing container), even when the liner is deployed, Anodizing treatment could not be omitted for the processing container.

International Publication WO2002 / 29877

  In recent years, there has been an increasing demand for larger substrates for FPDs, and plasma processing vessels tend to increase in size accordingly. At present, plasma processing containers for processing a huge substrate having a side exceeding 2 m have been manufactured, and it is becoming difficult to perform alumite processing on such a large plasma processing container. In addition, the work time and cost for performing the alumite treatment on a large plasma processing vessel has been a heavy burden.

  The present invention has been made in view of the above circumstances, and an object thereof is to reduce the working time and cost required for anodizing a plasma processing vessel as much as possible.

The plasma processing container according to the present invention is a plasma processing container that forms a processing chamber that accommodates an object to be processed and performs plasma processing,
A container body formed by joining a plurality of container components;
A first seal member deployed at a joint between the container components;
A protective member attached to the inner surface of the container body to protect the container body;
With
The first seal member and the protective member are brought into contact with each other at a joint portion between the container constituent members by inserting the protective member from the inside of the processing chamber to a position reaching the first seal member. It has the 1st seal part.

  The plasma processing container according to the present invention preferably has a second seal portion on the outside of the first seal member so that the second seal member is directly interposed between the container constituent members so as to surround the first seal member. . In this case, it is preferable that plasma and / or corrosive gas is blocked by the first seal portion, and the airtightness of the container body is maintained by the second seal portion. Furthermore, it is preferable that the first seal member and the second seal member are made of different materials, and the first seal member is made of a material resistant to plasma and / or corrosive gas. .

  Further, in the plasma processing container according to the present invention, the protection member is fitted into a recess formed in one of the two members to be joined, and the joint surface between the members and the surface of the protection member Are preferably formed flush with each other.

  Moreover, in the plasma processing container according to the present invention, it is preferable that the surface of the protective member is covered with an oxide film formed by alumite treatment or a ceramic sprayed film having plasma erosion resistance.

  A plasma processing apparatus according to the present invention includes the plasma processing container.

  According to the plasma processing container of the present invention, the first seal member is provided at the joint portion between the two container constituent members, and the protective member is inserted to reach the position of the first seal member. It was set as the structure which has the 1st seal | sticker part which made the member contact | abut to a protection member. According to such a seal structure, plasma and corrosive gas are blocked by the first seal portion. Therefore, plasma and corrosive gas do not reach the joint surface where the two container constituent members directly contact each other. For this reason, an alumite process becomes unnecessary about at least one among the container structural members joined, and the time and cost which an alumite process requires can be suppressed. Therefore, it is possible to reduce the working time and cost required for anodizing the plasma processing vessel, which has been a heavy burden in the past.

[First Embodiment]
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. With reference to FIG. 1 and FIG. 2, a plasma processing container according to the present embodiment and a plasma etching apparatus 100 including the plasma processing container will be described. FIG. 1 is a cross-sectional view showing a schematic configuration of a plasma etching apparatus 100. The plasma etching apparatus 100 is configured, for example, as an apparatus for performing a plasma etching process on an FPD glass substrate (hereinafter simply referred to as “substrate”) S. Examples of the FPD include a liquid crystal display (LCD), an electro luminescence (EL) display, a plasma display panel (PDP), and the like.

  As shown in FIG. 1, the plasma etching apparatus 100 is configured as a capacitively coupled parallel plate plasma etching apparatus that performs etching on a rectangular substrate S. The plasma etching apparatus 100 includes a processing container (container main body) 1 formed into a rectangular tube shape made of aluminum whose surface is anodized (anodized), for example. The processing container 1 which is a vacuum container is comprised by the lower container 2 which has the bottom wall 1a and the four side walls 1b, and the top plate 1c as a container structural member. The lower container 2 having the bottom wall 1a and the side wall 1b is integrally formed into a box shape by, for example, cutting or the like, and alumite treatment (anodization treatment) is performed on the surface. A liner 101 serving as a plate-like protective member is disposed on the inner surface of the side wall 1b in order to protect the side wall 1b from plasma and corrosive gas.

  The top plate 1c is configured to be openable / closable with respect to the lower container 2 by an opening / closing mechanism (not shown). On the inner surface (lower surface) of the top plate 1c, a liner 102 as a plate-shaped protective member is disposed in order to protect the top plate 1c from plasma and corrosive gas. An inner O-ring 111 as a first seal member is disposed at a position near the inside of the processing container 1 at a joint portion between the top plate 1c and the side wall 1b in a state where the top plate 1c is closed. An outer O-ring 112 as a second seal member is provided so as to surround 111. In other words, the inner O-ring 111 and the outer O-ring 112 are provided in a double manner to form a seal structure for the joint portion between the top plate 1c and the side wall 1b. The seal structure of this part will be described later. In the present embodiment, since the lower container 2 (the bottom wall 1a and the side wall 1b) is integrally formed, the inner O-ring 111 and the outer O-ring that seal the joint portion between the top plate 1c and the side wall 1b. By 112, the airtightness of the processing container 1 as a vacuum container is maintained with the top plate 1c closed.

  A frame-shaped insulating member 3 is disposed at the bottom in the processing container 1. A susceptor 5, which is a mounting table on which the substrate S can be mounted, is provided on the insulating member 3.

  The susceptor 5 which is also a lower electrode includes a base material 7. The base material 7 is made of a conductive material such as aluminum or stainless steel (SUS). The base material 7 is disposed on the insulating member 3, and a sealing member 13 such as an O-ring is provided at a joint portion between both members to maintain airtightness. The sealing member 14 also maintains airtightness between the insulating member 3 and the bottom wall 1 a of the processing container 1. The outer periphery of the side part of the base material 7 is surrounded by an insulating member 17. Thereby, the insulation of the side surface of the susceptor 5 is ensured, and abnormal discharge during plasma processing is prevented.

  Above the susceptor 5, a shower head 31 that functions as an upper electrode is provided in parallel to and opposite to the susceptor 5. The shower head 31 is supported by the top plate 1 c at the top of the processing container 1. The shower head 31 has a hollow shape, and a gas diffusion space 33 is provided therein. A plurality of gas discharge holes 35 for discharging a processing gas are formed on the lower surface of the shower head 31 (the surface facing the susceptor 5). The shower head 31 is grounded and forms a pair of parallel plate electrodes together with the susceptor 5.

A gas inlet 37 is provided near the upper center of the shower head 31. A processing gas supply pipe 39 is connected to the gas inlet 37. A gas supply source 45 for supplying a processing gas for etching is connected to the processing gas supply pipe 39 via two valves 41 and 41 and a mass flow controller 43. As the processing gas, for example, a rare gas such as Ar gas can be used in addition to a halogen-based gas or O ₂ gas.

  Exhaust ports 51 are formed at four locations at the four corners of the bottom of the processing container 1. An exhaust pipe 53 is connected to the exhaust port 51, and the exhaust pipe 53 is connected to an exhaust device 55. The exhaust device 55 includes a vacuum pump such as a turbo molecular pump, and is configured to be able to evacuate the processing container 1 to a predetermined reduced pressure atmosphere.

  In addition, a substrate transfer opening 61 is provided on one side wall 1b of the processing container 1 as an opening formed through the side wall 1b. The substrate transfer opening 61 is opened and closed by a gate valve (not shown). Then, the substrate S is carried in / out through the substrate carrying opening 61 with the gate valve opened. The other side wall 1b of the processing container 1 is provided with a window opening 63 as an opening penetrating the side wall 1b. A transparent quartz plate 65 is attached to each window opening 63.

  A power supply line 71 is connected to the base material 7 of the susceptor 5. A high frequency power source 75 is connected to the feeder line 71 via a matching box (MB) 73. Thereby, for example, high frequency power of 13.56 MHz is supplied from the high frequency power supply 75 to the susceptor 5 as the lower electrode. The power supply line 71 is introduced into the processing container via an opening 77 formed in the bottom wall 1a.

  A baffle plate 81 as a rectifying plate for controlling the gas flow in the processing container 1 is provided on the side of the susceptor 5. Four baffle plates 81 are provided corresponding to the four sides of the planar quadrangular susceptor 5. Each baffle plate 81 is supported substantially horizontally by an insulating wall 83 and an insulating wall 85 erected from the bottom wall 1 a of the processing container 1. The processing gas supplied from the gas discharge hole 35 of the shower head 31 toward the substrate S on the susceptor 5 diffuses in all directions on the surface of the substrate S, and the four portions of the bottom of the processing container 1 are rectified by the baffle plate 81. It is the structure which exhausts, forming the gas flow toward the exhaust port 51 provided in this.

  Next, the processing operation in the plasma etching apparatus 100 configured as described above will be described. First, in a state where a gate valve (not shown) is opened, a substrate S, which is an object to be processed, is carried into the processing container 1 through a substrate carrying opening 61 by a carrying device (not shown) and delivered to the susceptor 5. . Thereafter, the gate valve is closed, and the inside of the processing container 1 is evacuated to a predetermined degree of vacuum by the exhaust device 55.

  Next, the valve 41 is opened, and the processing gas is introduced from the gas supply source 45 into the gas diffusion space 33 of the shower head 31 through the processing gas supply pipe 39 and the gas introduction port 37. At this time, the mass flow controller 43 controls the flow rate of the processing gas. The processing gas introduced into the gas diffusion space 33 is further uniformly discharged to the substrate S placed on the susceptor 5 through the plurality of discharge holes 35, and the pressure in the processing container 1 becomes a predetermined value. Maintained.

  In this state, high frequency power is applied from the high frequency power supply 75 to the susceptor 5 through the matching box 73. As a result, a high frequency electric field is generated between the susceptor 5 as the lower electrode and the shower head 31 as the upper electrode, and the processing gas is dissociated into plasma. The substrate S is etched by this plasma.

  After performing the etching process, the application of the high frequency power from the high frequency power source 75 is stopped, the gas introduction is stopped, and then the inside of the processing container 1 is decompressed to a predetermined pressure. Next, the gate valve is opened, the substrate S is transferred from the susceptor 5 to a transfer device (not shown), and is transferred from the substrate transfer opening 61 of the processing container 1. With the above operation, the etching process on the substrate S is completed.

  FIG. 2 is an enlarged cross-sectional view of a portion A of FIG. 1 which is a joint portion between the side wall 1b and the top plate 1c. As described above, the joint portion between the side wall 1b and the top plate 1c is double-sealed by the inner O-ring 111 and the outer O-ring 112. The inner O-ring 111 and the outer O-ring 112 made of an elastic material such as rubber or fluororesin are mounted in a state of being fitted in O-ring disposing grooves 113 formed at the upper end of the side wall 1b.

  The liner 101 that protects the inner surface of the side wall 1b is detachably attached to the side wall 1b. The liner 102 that protects the inner surface of the top plate 1c is detachably attached to the top plate 1c. The liner 102 is fitted into a recess 114 formed with a step on the lower surface of the top plate 1c, and the surface of the liner 102 and the lower surface of the top plate 1c are flush with each other. The method for attaching the liners 101 and 102 to the side wall 1b and the top plate 1c is not particularly limited, and can be attached by a fixing means such as a screw.

The liner 102 attached to the top plate 1c is in contact with the upper end of the liner 101 attached to the side wall 1b, and the liner 101 and the liner 102 are arranged in a T shape in cross section. As the liner 101 and the liner 102, those obtained by subjecting the surface of an aluminum base material to alumite treatment (anodizing treatment) can be used. Further, it is also preferable to use a liner 101 and a liner 102 in which a ceramic sprayed film having plasma erosion resistance is formed on the surface of a base material such as aluminum. As the ceramic sprayed film having plasma erosion resistance, for example, a Y ₂ O ₃ sprayed film, a YF ₃ sprayed film, an Al ₂ O ₃ sprayed film, a B ₄ C sprayed film, or the like can be used. Among these, Y ₂ O ₃ sprayed film or YF ₃ sprayed film having excellent plasma erosion resistance is more preferable.

  The liner 102 is inserted between the side wall 1b and the top plate 1c from the inside of the processing container 1 at the joint portion between the side wall 1b and the top plate 1c, and the tip of the liner 102 reaches the inner O-ring 111. . That is, the inner O-ring 111 is not in contact with the top plate 1c but is in contact with the liner 102 to form the first seal portion at the joint portion between the side wall 1b and the top plate 1c. This first seal portion blocks plasma and corrosive gas at this site. Thus, the inner O-ring 111 serves to prevent plasma and corrosive gas from entering mainly into the gap between the joint portions of the side wall 1b and the top plate 1c, that is, blocks the plasma and corrosive gas. It has a function. On the other hand, the outer O-ring 112 is directly interposed between the side wall 1b and the top plate 1c to ensure the sealing performance of the joint portion between the two members, and to mainly maintain the airtightness of the processing chamber 1 as a vacuum chamber. have.

  The inner O-ring 111 and the outer O-ring 112 can be made of the same material. However, it is preferable to select a material having excellent resistance to plasma and corrosive gas, for example, silicone rubber and perfluoroelastomer, as the material of the inner O-ring 111 whose main purpose is to cut off plasma and gas. . On the other hand, as the material of the outer O-ring 112 whose main purpose is a vacuum holding function, it is preferable to select, for example, fluororubber because of its low gas permeability and low cost. As described above, the optimal operation of the inner O-ring 111 and the outer O-ring 112 is maximized by selecting the most suitable material according to the difference in function between the inner O-ring 111 and the outer O-ring 112 that are provided in a double manner. In addition, it can extend the period of use of the O-ring that is easily deteriorated.

  In the joining structure shown in FIGS. 1 and 2, plasma and corrosive gas are blocked at the position of the inner O-ring 111. Therefore, plasma or corrosive gas does not reach the joint boundary surface where the side wall 1b and the top plate 1c directly contact each other, for example, the position where the outer O-ring 112 for holding vacuum is disposed. For this reason, the top plate 1c is not exposed to plasma or corrosive gas, and anodizing is not required at all. Therefore, in plasma etching apparatus 100 of the present embodiment, the time and cost required for the alumite treatment of top plate 1c can be suppressed.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 3 is a sectional view showing a schematic configuration of a plasma etching apparatus 200 according to the second embodiment of the present invention. In the plasma etching apparatus 100 according to the first embodiment, the lower container 2 in which the bottom wall 1a and the side wall 1b are integrally molded and anodized on the surface is used. However, the plasma etching apparatus according to the present embodiment is used. In 200, the bottom wall 1a was comprised separately by the plate-shaped member, and the side wall 1b was comprised separately by the square tube-shaped member, respectively. Below, it demonstrates centering on difference with 1st Embodiment (FIG. 1), attaches | subjects the same code | symbol to the same structure, and abbreviate | omits description. In FIG. 3, the baffle plate 81, the insulating wall 83, and the insulating wall 85 are not shown.

  In the present embodiment, as shown in FIG. 3, the recess 121 is formed in the bottom wall 1a, and the liner 122 is fitted therein. An inner O-ring 131 serving as a first seal member is provided at a joint portion between the bottom wall 1a and the side wall 1b, and an outer O-ring 132 serving as a second seal member is provided so as to surround the inner O-ring 131. Has been deployed. In other words, the inner O-ring 131 and the outer O-ring 132 are provided in a double manner to form a seal structure for the joint portion between the bottom wall 1a and the side wall 1b.

  The liner 122 is inserted from the inside of the processing container 1 into a joint portion between the bottom wall 1 a and the side wall 1 b, and the tip thereof reaches the inner O-ring 131. That is, at the joint portion between the bottom wall 1a and the side wall 1b, the liner 122 directly contacts the inner O-ring 131 to form a first seal portion, and plasma and corrosive gas are blocked at this portion. As described above, the inner O-ring 131 mainly serves to prevent the plasma and corrosive gas from entering the gap between the bottom wall 1a and the side wall 1b, that is, the function of blocking the plasma and corrosive gas. Have. On the other hand, the outer O-ring 132 is directly interposed between the bottom wall 1a and the side wall 1b to form a second seal portion, ensuring the sealing performance of the joint portion between both members, and mainly a processing container as a vacuum chamber. It has a vacuum holding function for keeping the internal space of 1 airtight.

  The joining structure of the side wall 1b and the top plate 1c in the present embodiment is the same as that in the first embodiment.

  In the joining structure of the bottom wall 1 a and the side wall 1 b shown in FIG. 3, plasma and corrosive gas are blocked at the position of the inner O-ring 131. Therefore, the plasma and the corrosive gas do not reach the joint boundary surface where the bottom wall 1a and the side wall 1b are in direct contact, for example, the position where the outer O-ring 132 for vacuum holding is disposed. For this reason, the alumite process about the bottom wall 1a becomes unnecessary, and the time and cost required for the alumite process of the bottom wall 1a can be suppressed. In the present embodiment, as in the first embodiment, the alumite treatment of the top plate 1c is not necessary. Further, in the present embodiment, since the side wall 1b is formed of a rectangular tube-like member, a secondary effect that the alumite treatment can be easily performed on the inner surface of the side wall 1b is also obtained.

  Other configurations, operations, and effects in the present embodiment are the same as those in the first embodiment.

[Third Embodiment]
Next, a third embodiment of the present invention will be described with reference to FIG. The present embodiment is a modification of the first and second embodiments described above, and the plasma etching of the first and second embodiments is used as it is, except that the arrangement position of the second seal member is changed. The present invention can be applied to the devices 100 and 200. Below, it demonstrates centering on difference with 1st and 2nd embodiment (FIG. 1 and FIG. 2), attaches | subjects the same code | symbol to the same structure, and abbreviate | omits description.

  FIG. 4 is an enlarged cross-sectional view showing a joint portion between the side wall 1b and the top plate 1c. A liner 102 as a plate-shaped protective member is disposed on the inner surface (lower surface) of the top plate 1c. The liner 102 is inserted between the side wall 1b and the top plate 1c from the inside of the processing container 1 at the joint portion between the side wall 1b and the top plate 1c. An O-ring 141 as a first seal member is disposed at a position close to the inside of the processing container 1 on the side wall 1b side at a joint portion between the top plate 1c and the side wall 1b with the top plate 1c closed. Yes. The O-ring 141 is disposed in contact with the lower surface of the liner 102. The O-ring 141 has a role of preventing plasma and corrosive gas from entering the gap between the side wall 1b and the top plate 1c (function of blocking plasma and corrosive gas). In addition, a sealing function is ensured between the liner 102 and the side wall 1b, and a vacuum holding function for maintaining the airtightness of the processing container 1 as a vacuum chamber is provided.

  Further, an O-ring 142 is disposed between the liner 102 and the top plate 1c. The O-ring 142 is disposed in contact with the upper surface of the liner 102. The O-ring 142 has a vacuum holding function that ensures sealing performance on the back side of the liner 102 (that is, between the liner 102 and the top plate 1c) and maintains the airtightness of the processing container 1 as a vacuum chamber. .

  In the joining structure of the side wall 1b and the top plate 1c shown in FIG. 4, plasma and corrosive gas are blocked at the position of the O-ring 141. Therefore, plasma and corrosive gas do not reach the joint interface where the side wall 1b and the top plate 1c directly contact each other. For this reason, the alumite process about the top plate 1c becomes unnecessary, and the time and cost which an alumite process of the top plate 1c requires can be suppressed.

  Other configurations, operations, and effects in the present embodiment are the same as those in the first embodiment. Moreover, the joining structure of the side wall 1b and the top plate 1c shown in FIG. 4 can be applied to the joining structure of the bottom wall 1a and the rectangular tubular side wall 1b in the plasma etching apparatus 200 of the second embodiment. is there.

  As mentioned above, although embodiment of this invention was described, this invention is not restrict | limited to the said embodiment, A various deformation | transformation is possible. For example, in the above embodiment, the RIE type capacitively coupled parallel plate plasma etching apparatus that applies high frequency power to the lower electrode (base material 7) has been described as an example. There may also be inductive coupling type without being limited to capacitive coupling type.

  Further, the plasma processing container of the present invention is not limited to a plasma etching apparatus for processing an FPD substrate, but may be a semiconductor wafer, for example, and is not limited to a plasma etching apparatus, for example, plasma ashing. The present invention can also be applied to other plasma processing apparatuses such as an apparatus and a plasma CVD apparatus.

It is sectional drawing which shows schematic structure of the plasma etching apparatus which concerns on the 1st Embodiment of this invention. It is principal part sectional drawing which expands and shows the A section of FIG. It is sectional drawing which shows schematic structure of the plasma etching apparatus which concerns on the 2nd Embodiment of this invention. It is principal part sectional drawing of the plasma etching apparatus which concerns on the 3rd Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Processing container, 1a ... Bottom wall, 1b ... Side wall, 1c ... Top plate, 2 ... Lower container, 3 ... Insulating member, 5 ... Susceptor, 7 ... Base material, 51 ... Exhaust port, 61 ... Opening for board | substrate conveyance, DESCRIPTION OF SYMBOLS 100 ... Plasma etching apparatus, 101 ... Liner, 102 ... Liner, 111 ... Inner O-ring, 112 ... Outer O-ring, 113 ... O-ring arrangement groove, 114 ... Recess

Claims (7)

A plasma processing container for forming a processing chamber for accommodating a target object and performing plasma processing,
A container body formed by joining a plurality of container components;
A first seal member and a second seal member disposed at a joint portion between the container constituent members;
A protective member attached to the inner surface of the container body to protect the container body;
With
The first seal member and the protective member are brought into contact with each other at a joint portion between the container constituent members by inserting the protective member from the inside of the processing chamber to a position reaching the first seal member. and have a first seal portion,
A plasma processing container having a second seal part in which the second seal member is directly interposed between the container constituent members on the outside so as to surround the first seal member . By the first seal portion blocks the plasma and / or corrosive gases, by the second sealing portion, the plasma processing vessel according to claim 1, characterized in that to maintain the airtightness of the container body . The first seal member and the second seal member are different in material, and the first seal member is made of a material resistant to plasma and / or corrosive gas. The plasma processing container according to claim 2 . The protection member is fitted into a recess formed in one of the two members to be joined, and the joining surface between the members and the surface of the protection member are formed flush with each other. the plasma processing chamber according to claims 1, wherein any one of claims 3. Surface of the protective member, the plasma processing chamber according to claims 1, characterized in that it is covered by the ceramics sprayed film having an oxide film or plasma erosion resistance, by alumite treatment to any one of claims 4 . The plasma processing container according to claim 5, wherein the protection member is formed in a plate shape and is detachably attached to the container body.   A plasma processing apparatus comprising the plasma processing container according to claim 1.

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