JP4187073B2 - Sealing device for a processing device using a rotary table - Google Patents

Description

  The present invention is a processing apparatus for performing cleaning processing of a substrate (semiconductor wafer, electronic device substrate, liquid crystal substrate, photomask, glass substrate, etc.) using a rotary table, and a processing region in which the rotary table is disposed. In particular, it relates to a sealing device installed in a processing apparatus that requires a high degree of contamination prevention measures. Specifically, a rotary table is arranged between the rotary table and a cover that covers the rotary shaft. The present invention relates to a sealing device provided to shield a processing area and an in-cover area.

For example, when a substrate such as a semiconductor wafer is cleaned using a rotary table, it is necessary to keep the processing area where the rotary table is placed clean, and particles enter the processing area from the drive side of the rotary table. It is necessary to prevent this. Therefore, in a processing apparatus that requires such a high level of contamination prevention measures, a processing in which a rotary table is conventionally arranged between the rotary table and a cover that covers the drive side including the rotary shaft is conventionally performed. It has been proposed to provide a seal device that shields the region and the cover inner region, and as such a seal device, a labyrinth seal or a magnetic fluid seal is generally employed (see, for example, Patent Document 1). Thus, by providing such a sealing device, particles are prevented from entering from the cover inner region to the processing region and the substrate or the like is not contaminated, and the processing residue (cleaning liquid) generated in the processing region is prevented. Or harmful substances intrude into the cover area and cause troubles in the drive system of the rotating shaft.
JP-A-11-265868

  However, depending on the sealing device such as the labyrinth seal used in the conventional processing apparatus, the processing area and the cover inner area cannot be sufficiently shielded, and it is possible to prevent contamination in the processing apparatus such as the substrate cleaning apparatus. The fact is that we cannot expect. That is, in the labyrinth seal, the annular gap constituting the labyrinth is likely to be non-uniform depending on the rotation accuracy and the equipment accuracy, and the shielding function between the two regions is not sufficiently exhibited due to the respiratory action resulting from the non-uniform labyrinth gap. In addition, since the quality of the magnetic fluid seal is unstable, it is difficult to exert a sufficient sealing function like the labyrinth seal.

  The present invention has been made in view of the above points, and can reliably shield a processing area in which a rotary table is arranged and an in-cover area in which a drive system including a rotating shaft is arranged, and is highly contamination-free. It is an object of the present invention to provide a sealing apparatus for a processing apparatus using a rotary table, which can perform a process such as substrate cleaning required for the above-mentioned without causing a sealing problem.

The present invention relates to a processing area in which a rotary table is disposed between a rotary table and a cover that covers the rotary shaft and includes a non-metallic cover main body and a metal seal flange attached thereto. in order to shield the cover region, a sealing device installed, the rotary seal ring fixed to the rotary table at an rotating shaft concentric state opposed to the rotary seal ring forms an axis of rotation concentric A stationary seal ring that is held axially movable on the seal flange , a spring member that is disposed in the cover and presses and urges the stationary seal ring to the rotary seal ring, a cover body, a seal flange, and a stationary seal ring A series of sealing gas passages that open between the sealing end faces that are the opposite end faces of both sealing rings, and cause the sealing gas to be ejected from the sealing gas passages between the sealing end faces. More, while maintaining a non-contact state, said between both areas is a non-contact type mechanical seal configured to shield seals, a stationary seal ring, the part forming the Configure substrate with carbon and sealing end faces The surface layer of the substrate to be removed is a composite structure composed of a glassy carbon layer or a synthetic resin layer including the inner peripheral surface layer of the seal gas passage, and the surface of the seal flange in contact with the seal gas and the processing region. The present invention proposes a sealing device for a processing apparatus using a rotary table, characterized in that the portion to be coated is coated with a fluororesin to prevent generation of particles due to contact with a sealing gas . In such a sealing device, depending on the sealing conditions, a dynamic pressure generating groove is formed on the sealing end face of one sealing ring, and the dynamic pressure generated by the dynamic pressure generating groove acts on the sealing end face in addition to the static pressure by the seal gas. By doing so, it is preferable that the sealing end faces are held in a non-contact state.

According to a first aspect of the present invention, there is provided a non-contact type mechanical seal that ejects seal gas from between a rotary sealing ring on the rotary table side and a stationary sealing ring on the cover side to a processing region and a cover inner region. Because it is configured, it is more reliable than the processing area where the rotary table is arranged and the area inside the cover where the rotating shaft driving means is arranged, as compared with the case where the labyrinth seal described at the beginning is used. It can be shielded. Therefore, by using the sealing device of the present invention, it is possible to keep the processing in the processing region in a clean atmosphere in which the particle intrusion from the cover inner region is completely prevented, and to perform the processing such as cleaning the substrate satisfactorily. And can implement advanced anti-contamination measures. In addition, it is possible to eliminate problems such as cleaning liquid residues generated in the processing area and harmful substances used and generated in the processing area leaking into the cover area and adversely affecting the drive system of the rotating shaft. In particular, by forming the stationary sealing ring and the cover (cover body and seal flange) as described in claim 1 , it is possible to prevent the generation of particles from the sealing device side and to prevent contamination of the processing area. Can be performed more effectively. Furthermore, as described in claim 2, the sealing function between the sealing end faces is maintained in a non-contact state by the action of the dynamic pressure by the dynamic pressure generating groove in addition to the static pressure by the sealing gas. The contamination-free function can be further improved.

  FIG. 1 shows an example of a sealing device for a processing apparatus using a turntable according to the present invention. A substrate such as a semiconductor wafer, a substrate of an electronic device, a liquid crystal substrate, a photomask, or a glass substrate is attached to the turntable 1. In the substrate cleaning apparatus to be used and cleaned, the substrate cleaning apparatus is provided between the rotary table 1 and the cover 3 covering the rotary shaft 2 so as to shield the processing area A where the rotary table 1 is arranged and the in-cover area B. The sealing device 4 is shown.

  As shown in FIG. 1, the rotary table 1 has a disk shape arranged horizontally in the processing area A, and is rotationally driven by a rotary shaft 2 connected to the center thereof. As shown in FIG. 1, the rotary shaft 2 extends in the vertical direction and is driven to rotate by a driving means (motor or the like) (not shown).

  As shown in FIG. 1, the cover 3 includes a cover main body 6 that opens at the upper end and a seal flange 7 that is attached to the upper end opening 6a. The cover body 6 is arranged with the upper end (the upper end of the opening 6a) close to the lower surface of the turntable 1, and covers the rotary shaft 2, its driving means, bearing means and the like. The inner and outer peripheral surfaces of the upper end opening 6 a of the cover body 6 are cylindrical surfaces that are concentric with the rotary shaft 2. An annular protrusion 1b is provided on the lower surface of the turntable 1 so as to face the outer peripheral surface of the upper end opening 6a. The seal flange 7 is made of metal (for example, made of stainless steel such as SUS316) made of a cylindrical sealing ring holding portion 7a and an annular spring holding portion 7b projecting inward from the lower end of the sealing ring holding portion 7a. The seal ring holding portion 7a is fitted to the upper end opening 6a of the cover body 6 via a pair of fluororubber O-rings 8 and 8 arranged in the vertical direction, and the spring holding portion 7b. Is fixed to the inner partition wall 6b of the cover body 6 with bolts 5 so that it is attached to the upper end opening 6a of the cover body 6 concentrically with the rotary shaft 2. The upper end portion of the sealing ring holding portion 7a and the upper end portion of the cover body 6 are flush with each other. The surface 71 of the sealing ring holding part 7a is coated with a fluororesin as shown in FIG.

  Thus, as shown in FIG. 1, the seal device 4 is concentric with the rotary shaft 2 and fixed to the rotary table 1, and is concentric with the rotary shaft 2 and faces the rotary seal ring 9. A stationary seal ring 10 that is axially movable and relatively non-rotatable in the cover 3, and a spring member that is disposed in the cover 3 and presses and urges the stationary seal ring 10 to the rotary seal ring 9. 11 and a series of sealing gas passages 12 that pass through the cover 3 and the stationary sealing ring 10 and open between the sealing end surfaces 9a and 10a, which are the opposite end surfaces of the sealing rings 9 and 10, respectively. A static pressure type non-contact configured to shield and seal between the regions A and B while maintaining a non-contact state by ejecting a seal gas G from the seal gas passage 12 to the space 10a. Type mechanical seal, that is, static pressure type It is a contact gas seal.

  The rotary seal ring 9 is an annular body made of a hard material (in this example, silicon carbide) from a base material (carbon) of a stationary seal ring 10 to be described later. As shown in FIGS. 1 is fixed to a lower surface portion of 1 through a mounting ring 13 made of metal (for example, stainless steel such as SUIS316) and an O-ring 14 made of fluororubber. The attachment ring 13 is attached to the lower surface portion of the rotary table 1 with bolts 15 with the outer peripheral portion engaged with the inner peripheral portion of the lower end of the rotary seal ring 9, and the rotary seal ring 9 is attached to the lower surface of the rotary table 1. It is pressed and fixed to the part. The O-ring 14 is sandwiched between the inner peripheral portion of the upper end of the rotary seal ring 9 and the rotary table 1, and performs a secondary seal between the two 1 and 9. The lower end surface of the rotary seal ring 9 is polished to a smooth annular surface, and the portion excluding the portion with which the mounting ring 13 engages functions as a seal end surface (hereinafter also referred to as “rotary seal end surface”) 9a.

  As shown in FIGS. 1 and 2, the stationary sealing ring 10 is an annular body having a sealing end surface 10a whose upper end surface is polished to a smooth annular surface (hereinafter also referred to as “stationary sealing end surface”), and is parallel in the vertical direction. A pair of fluororubber O-rings 16 and 16 are fitted and held in the seal ring holding portion 7a of the seal flange 7 so as to be movable in the axial direction (movable in the vertical direction). The outer diameter of the stationary sealing end face 10a is set slightly smaller than the outer diameter of the rotating sealing end face 9a, and the inner diameter of the stationary sealing end face 10a is set slightly larger than the inner diameter of the rotating sealing end face 9a. Each O-ring 16 is engaged and held in an annular O-ring groove 10 b formed on the outer peripheral portion of the stationary sealing ring 10. Further, a circular hole 10c extending in the axial direction is formed at the lower end of the stationary seal ring 10, and a metal (for example, stainless steel such as SUS316) implanted in the spring holding part 7b of the seal flange 7 in the circular hole 10c. By engaging a steel drive pin 17, the stationary seal ring 10 is held in a non-rotatable manner relative to the cover 3 (seal flange 7) while allowing its axial movement within a predetermined range. . In addition, the number of the circular holes 10c and the drive pins 17 that engage with the circular holes 10c is arbitrary, and a plurality of them are provided as necessary.

  As shown in FIG. 1, the spring member 11 is composed of a plurality of coil springs (only one is shown) interposed between a stationary seal ring 10 and a lower spring holding portion 7b. The ring 10 is pressed and urged to the rotary sealing ring 9 to generate a closing force that acts in the direction of closing the sealing end faces 9a and 10a.

  As shown in FIG. 1, the seal gas passage 12 includes a static pressure generating groove 18 formed in the stationary sealing end surface 10a, an outer peripheral surface of the stationary sealing ring 10, and an inner peripheral surface of the sealing ring holding portion 7a of the sealing flange 7. An annular communication space 19 formed therebetween, cover-side seal gas passages 20 and 21 extending through the cover 3 to the communication space 19, and a static pressure generating groove 18 from the communication space 19 through the stationary seal ring 10. And a sealing ring side seal gas passage 22 leading to The static pressure generating groove 18 is a shallow concave groove that is continuous or intermittently formed in a concentric ring shape with the stationary sealing end face 10a. In this example, the latter is adopted. That is, as shown in FIG. 4, the static pressure generating groove 18 is composed of a plurality of arc-shaped concave grooves 18 a that are concentrically arranged in parallel with the stationary sealing end face 10 a. The communication space 19 is an annular space formed between the opposed peripheral surfaces of the sealing ring holding portion 7 a and the stationary sealing ring 10, and is sealed by O-rings 16 and 16. The vertical width (interval between the O-rings 16, 16) of the communication space 19 is such that the communication space 19 and a first cover-side seal gas passage 20 (to be described later) are aligned with the vertical movement required for the stationary seal ring 10. It is set as appropriate as long as the connection is not released. The cover-side seal gas passage includes a first cover-side seal gas passage 20 that passes through the seal ring holding portion 7a of the seal flange 7 in the radial direction and communicates with the communication space 19, and the cover body 6 and passes through the first cover side. The second cover side seal gas passage 21 communicates with the seal gas passage 20. The communicating portions of the cover-side seal gas passages 20 and 21 are sealed by the O-rings 8 and 8. The upstream end of the sealing ring side seal gas passage 22 is opened to the communication space 19, and the downstream end of the sealing ring side seal gas passage 22 is branched. As shown in FIG. Each arcuate groove 18a constituting the generating groove 18 is opened. The upstream end of the second cover-side seal gas passage 21 is connected to a predetermined seal gas supply source (not shown), and a clean seal gas G that is higher in pressure than both regions A and B and does not contain particles The two-cover-side seal gas passage 21, the first cover-side seal gas passage 20, the communication space 19, and the sealing ring-side seal gas passage 22 are supplied to the static pressure generating groove 18. As the sealing gas G, a gas that does not have any adverse effect even if it flows into the areas A and B is appropriately selected according to the sealing conditions. In this example, clean nitrogen gas that is inert to various substances and harmless to the human body is used. Seal gas G is generally supplied only during operation of rotary table 1 (during driving of rotary shaft 2), and is stopped after the operation is stopped. The operation of the rotary table is started after the supply of the seal gas G is started and after the sealed end faces 9a and 10a are maintained in a proper non-contact state. This is performed after the operation of the table is stopped and after the rotary shaft 2 is completely stopped. If necessary, the supply of the sealing gas G can be continued regardless of whether the turntable 1 is started or stopped. Further, a restrictor such as an orifice is provided at an appropriate position of the seal gas passage 12 (for example, an upstream portion of the seal ring-side seal gas passage 22) as necessary.

  Thus, when the sealing gas G is supplied to the static pressure generating groove 18, an opening force is generated between the sealing end faces 9a and 10a that is opened by the sealing gas G introduced into the static pressure generating groove 18. . This opening force is due to the static pressure generated by the sealing gas G introduced between the sealed end faces 9a and 10a. Therefore, the sealing end surfaces 9a and 10a are held in a non-contact state in which the opening force and the closing force (spring load) by the spring member 11 acting in the direction in which the sealing end surfaces 9a and 10a are closed are balanced. That is, the sealing gas G introduced into the static pressure generating groove 18 forms a static pressure fluid film between the sealed end faces 9a and 10a, and due to the presence of this fluid film, the outer peripheral side area (processing area) of the sealed end faces 9a and 10a. ) Between A and the inner peripheral side region (cover inner region) B is shield-sealed. The pressure of the sealing gas G and the spring force (spring load) of the spring member 11 are appropriately set according to the sealing conditions so that the gap between the sealed end faces 9a and 10a is appropriate (generally 5 to 15 μm). Is done.

  By the way, the stationary sealing ring 10 is required to have further workability in order to minimize damage to the sealing end face due to contact with the mating sealing ring (rotating sealing ring) 9 (the stationary sealing ring 10 is a seal). Since the gas passage 12, that is, the static pressure generating groove 18 and the seal ring-side seal gas passage 22, need to be formed, it has a complicated shape compared to the rotary seal ring 9 having a simple annular shape. Therefore, it is generally composed of carbon that is soft and rich in workability. However, when a stationary seal ring made of carbon is used, fine particles are likely to be generated from the carbon surface by the seal gas G passing through the seal gas passage 12, and these particles together with the seal gas G are processed from the sealed end faces 9a and 10a to the processing region. There is a risk of entering A (and the in-cover region B). Therefore, it is preferable to prevent such intrusion of particles from the carbon stationary seal ring 10 in order to take a higher level of contamination prevention measures. Therefore, in this example, as shown in FIGS. 2 and 3, the stationary sealing ring 10 is made of carbon, and the surface layer of the base 101 is made of glass except for the portion forming the stationary sealing end face 10 a. The composite material structure is composed of the carbon-like carbon layer 102.

  That is, the stationary sealing ring 10 is manufactured by manufacturing a static sealing ring-shaped carbon base 101 in which a static pressure generating groove 18 and a sealing ring side seal gas passage 22 are formed, and the entire surface of the base 101 (seal gas passage 18, 22 and through holes such as circular holes 10c and the inner peripheral surfaces of the recesses) are coated or impregnated with glassy carbon, and a portion corresponding to the stationary sealing end surface 10a is polished so that the carbon is exposed. The glassy carbon layer 102 can be formed by a well-known method. For example, an appropriate synthetic resin is dissolved in an organic solvent to obtain a precursor solution, and the precursor solution is impregnated or applied on the surface of the substrate 101, dried, and then heated and cured in an inert atmosphere or a vacuum atmosphere. And firing. Alternatively, the substrate 101 may be impregnated or / and coated with a liquid synthetic resin as it is and cured by heating, followed by further baking. The synthetic resin used is not particularly limited as long as it becomes a glassy carbonaceous material after firing. For example, phenol synthetic resin, furan synthetic resin, polyamide synthetic resin, polyimide synthetic resin, polyamideimide synthetic resin, polycarbodiimide synthetic resin Epoxy synthetic resin, urea synthetic resin, melamine synthetic resin, unsaturated polyester synthetic resin, xylene synthetic resin, alkyd synthetic resin, vinyl chloride synthetic resin and the like can be used. Moreover, as an organic solvent for obtaining a precursor solution, what is necessary is just to melt | dissolve the synthetic resin to be used, for example, tetrachloroethylene, trichloroethylene, dimethylacetamide, N-methylpyrrolidone, ketones (acetone, methyl ethyl ketone, etc.), Alcohols (methanol, ethanol, etc.) can be used. For example, tetrachloroethylene is used for the polycarbodiimide synthetic resin, methanol is used for the phenol synthetic resin, and N-methylpyrrolidone is used for the polyamideimide synthetic resin. The above-mentioned solvent can use what mixed 2 or more types according to the synthetic resin to be used.

  In the substrate cleaning apparatus as a processing apparatus using the non-contact type mechanical seal (static pressure type non-contact gas seal) 4 configured as described above, the rotary sealing ring 9 provided on the rotary table 1 and the cover 3 are provided. Since the sealing gas G is ejected to both areas A and B from between the sealing end faces 9a and 10a, which are opposed to the stationary sealing ring 10 provided, the area between the processing area A and the in-cover area B is completely blocked. Will be. Moreover, since both the sealing end surfaces 9a and 10a are held in a non-contact state by the sealing gas G, particles such as abrasion powder due to the contact between the sealing end surfaces 9a and 10a are not generated. Therefore, dust generated in the in-cover area B does not enter the processing area A, and the processing area A is kept clean. Conversely, the processing residue generated in the processing area A does not enter the in-cover area B, and the drive system of the rotating shaft 2 does not cause trouble.

  Further, since the inner peripheral surface layer 102a of the seal gas passage 12 (static pressure generating groove 18 and seal ring-side seal gas passage 22) formed in the stationary seal ring 10 is made of glassy carbon, the base 101 is made of carbon. Regardless of the product made, carbon powder is not generated by contact with the seal gas G passing through the seal gas passage 12. Therefore, no particles are generated from the stationary seal ring 10, and the processing area A can be more effectively cleaned.

  Further, since the outer peripheral surface layer 102b of the stationary seal ring 10 is composed of glassy carbon including the inner peripheral surface layer of the O-ring groove 10b, the stationary seal ring 10 through the O-rings 16 and 16 is used. Is smoothly moved in the axial direction. For this reason, the followability of the stationary sealing ring 10 is improved, the sealed end faces 9a and 10a are maintained in a proper non-contact state, and the sealing function by the non-contact type mechanical seal 4 is exhibited well. In addition, since the portion in contact with the sealing gas G passing through the communication space 19 is also composed of the glassy carbon layer 102b, no carbon powder is generated in the communication space 19.

  Further, since the lower end surface of the stationary sealing ring 10 including the inner peripheral surface of the circular hole 10c is also covered with the glassy carbon layer 102c, carbon powder is generated by contact between the stationary sealing ring 10, the drive pin 17, and the spring member 11. It does not occur, and particles are not generated as much as possible in the in-cover region B, and there is no possibility that the driving system of the rotating shaft 2 or the like may cause trouble due to the carbon powder. Further, since the contact portion with the spring member 11 and the drive pin 17 is covered with the hard glassy carbon layer 102c, the stationary seal ring 10 may be worn and damaged by the contact with the spring member 11 and the drive pin 17. The durability of the stationary seal ring 10 is improved.

  In the processing apparatus (substrate cleaning apparatus) described above, the part of the processing area A that contacts the fluid and the seal gas G is all made of a nonmetallic material or coated with a nonmetallic material. That is, the rotary seal ring 9 is made of silicon carbide, the O-rings 8, 14 and 16 are made of fluoro rubber, and the portion of the seal flange 7 facing the processing region A and the portion in contact with the seal gas G ( The surface portion of the sealing ring holding part 7 a is a fluororesin coating layer 71. Further, the turntable 1 and the cover body 6 are also made of a non-metallic material, or the portion facing the region to be processed A and the portion contacting the seal gas G3 are coated with a non-metallic material. On the other hand, the spring member 11 and the drive pin 17 made of metal are all disposed in the in-cover region B. Therefore, even when the object to be processed does not like metal ions such as a semiconductor wafer, the processing can be performed satisfactorily.

  The sealing device for a processing apparatus using the rotary table of the present invention is not limited to the above-described configuration, and can be appropriately improved and modified without departing from the basic principle of the present invention.

  For example, in the example shown in FIGS. 1 to 3, the sealing device is configured as a static pressure type non-contact gas seal 4 that holds the sealing end surfaces 9 a and 10 a in a non-contact state only by a static pressure by the sealing gas G. As shown in FIGS. 5 and 6, the sealing end faces 9a and 10a are combined with a static pressure to generate a dynamic pressure to generate a dynamic pressure, thereby maintaining a non-contact mechanical seal as a non-contact type mechanical seal 41. It may be configured.

  That is, in the composite non-contact gas seal 41 shown in FIGS. 5 and 6, the dynamic pressure generating groove 91 is formed on the sealing end surface (rotating sealing end surface) 9a of the rotating sealing ring 9 which is one sealing end surface. The dynamic pressure generating groove 91 is configured to generate dynamic pressure between the sealed end faces 9a and 10a. The shape of the dynamic pressure generating groove 91 can be appropriately set according to the sealing conditions and the like, but in this example, the dynamic pressure generating groove 91 is formed on the static seal end surface 9a as shown in FIG. 7 or FIG. The first groove portion 92a extending from the portion facing the pressure generating groove 18 in the outer diameter direction and in the direction opposite to the rotation direction (a direction) of the rotary seal ring 9 and the rotation of the rotary seal ring 9 in the inner diameter direction. A plurality of grooves 92 including second groove portions 92 extending in an inclined direction in the direction opposite to the direction (a direction) are configured in parallel with the circumferential direction of the sealed end surface 9a. Each groove 92 is a groove having a shallow depth of 1 to 10 μm, and has an outermost diameter side end portion (an outer diameter side end portion of the first groove portion 92a) and an innermost diameter side end portion (the second groove portion 9b of the second groove portion 9b). As shown in FIG. 6, the inner diameter side end portion is located in the overlapping region of both sealed end faces 9a and 10a. That is, the inner and outer diameters E and F of the dynamic pressure generating groove 91 are the outer diameter (≦ outer diameter of the rotating sealing end surface 9a) A and the inner diameter (≧ rotating sealing end surface) of the sealing end surface (stationary sealing end surface) 10a of the stationary sealing ring 10. 9a) (D) and the outer diameter B of the static pressure generating groove 18 (arc-shaped concave groove 18a) and the inner diameter C thereof are appropriately set within a range where B <F <A, D <E <C. Has been. In this example, the condition of 0.5 ≦ (F−B) / (A−B) ≦ 0.9 or 0.5 ≦ (C−E) / (C−BD) ≦ 0.9 is satisfied. Is set. As shown in FIG. 7, each groove 92 has a substantially square shape in which the first groove portion 92a and the second groove portion 92b coincide with each other at the base end portion, or as shown in FIG. The base end portions of the portion 92a and the second groove portion 92b have a zigzag shape that folds in the circumferential direction.

  According to such a composite non-contact gas seal 41, dynamic pressure is generated by the dynamic pressure generating groove 91 in addition to the static pressure by the seal gas G between the sealed end faces 9a and 10a, and due to these static pressure and dynamic pressure. The sealed end faces 9a and 10a are kept in a non-contact state. Accordingly, even when a situation occurs in which the sealed end faces 9a and 10a cannot be held in an appropriate non-contact state depending on the static pressure generated by the seal gas G, the proper non-contact state can be maintained by the dynamic pressure. Further, the required supply amount of the seal gas G can be reduced by the static pressure by the seal gas G, as compared with the static pressure type non-contact gas seal 4 which is kept in a non-contact state only by the static pressure. Further, since the dynamic pressure generating groove 91 is not opened outside the overlapping region of the sealed end surfaces 9a and 10a, the innermost diameter side end portion and the outermost diameter side end portion of each groove 92 are introduced between the sealed end surfaces 9a and 10a. In addition to functioning as a weir against the sealed gas G, the leakage gap formed between the sealed end faces 9a and 10a is reduced. As a result, the amount of sealing gas G introduced between the sealing end faces 9a, 10a to the processing region (sealed gas region) A side is suppressed, and the trapping characteristic of the sealing gas G by the dynamic pressure generating groove 91 is extremely good. It will be something. Therefore, the consumption of the sealing gas G can be reduced, and even if there are particles accompanying the sealing gas G, the intrusion can be suppressed as much as possible.

  5 is the same as that of the sealing device 4 and the substrate cleaning device shown in FIG. 1 except for the above-described configuration (the point where the dynamic pressure generating groove 91 is provided). Are the same.

  By the way, depending on the configuration and use conditions of the processing apparatus equipped with the composite non-contact gas seal 41 as the sealing apparatus shown in FIG. 5, the rotary table 1 or the rotating shaft 2 may be rotated in both directions instead of one direction. However, in such a case, the dynamic pressure generating groove 91 may be shaped so that dynamic pressure can be generated even when the rotary seal ring 9 rotates in either the forward direction or the reverse direction. The shape of the dynamic pressure generating groove 91 can be arbitrarily set according to the sealing conditions and the like, and various shapes have been proposed conventionally. For example, a dynamic pressure generating groove unit composed of a first dynamic pressure generating groove and a second dynamic pressure generating groove, which are arranged in the radial direction and symmetrical with respect to the diameter line, is arranged at a predetermined interval in the circumferential direction on the rotary sealing end surface 9a. When the rotary seal ring 9 rotates in the forward direction, dynamic pressure is generated by the first dynamic pressure generating groove, and when the rotary seal ring 9 rotates in the reverse direction. The configuration is such that the dynamic pressure is generated by the second dynamic pressure generating groove. As each of the first and second dynamic pressure generating grooves, for example, an L-shaped groove having a constant groove depth and groove width can be employed.

  Further, in the structure of the stationary sealing ring 10 of the sealing devices 4 and 41 described above, instead of the glassy carbon layer 102, the surface layer of the base 101 is a synthetic resin layer formed by coating or impregnating an appropriate synthetic resin. It is also possible. Further, the glassy carbon layer 102 (or the synthetic resin layer) is formed at least on the inner peripheral surface of the static pressure generating groove 18 and the stationary seal ring side seal gas passage 22, but as shown in FIG. It is also possible to form the entire surface including the stationary sealing end face 10a. However, as shown in FIGS. 2 and 3, if the carbon is exposed without covering the stationary sealing end face 10a with the glassy carbon layer 102 (or the synthetic resin layer), the supply of the sealing gas G may be stopped or the shaft may run out. There is an advantage that the stationary sealing end face 10a can be easily repaired even when the rotating sealing end face 9a is damaged due to contact. Furthermore, as shown in FIG. 10, glassy carbon (or synthetic resin) may be impregnated into the stationary seal ring 10. In this case, the glassy carbon layer 102 (or the synthetic resin layer) need not be thicker than necessary.

  Further, the rotary seal ring 9 may be fixed to the rotary shaft 2 or its sleeve in addition to being provided on the rotary shaft side portion (for example, the rotary table 1) other than the rotary shaft 2. Further, depending on the sealing conditions, the stationary seal ring 10 can be fixed to the seal case 7, and the rotary seal ring 9 can be held axially movable on the rotary shaft side but not relatively rotatable.

It is a vertical side view which shows an example of the processing apparatus which uses the rotary table equipped with the sealing device which concerns on this invention. FIG. 2 is a detailed view showing a main part of FIG. 1. It is a vertical side view which takes out and shows the principal part (stationary sealing ring) of FIG. It is a top view of the stationary sealing ring shown in FIG. It is a vertical side view which shows the modification of the processing apparatus which equips the sealing apparatus which concerns on this invention, and uses a rotary table. It is detail drawing which shows the principal part of FIG. FIG. 5 is a half-top view of a rotary seal ring showing an example of a dynamic pressure generating groove. FIG. 6 is a half-top view of a rotary seal ring showing a modification of the dynamic pressure generating groove. It is a vertical side view equivalent to FIG. 3 which shows the modification of a stationary sealing ring. It is a vertical side view equivalent to FIG. 3 which shows the other modification of a stationary sealing ring.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Rotary table, 2 ... Rotating shaft, 3 ... Cover, 4 ... Sealing device (static pressure type non-contact gas seal), 6 ... Cover main body, 7 ... Seal flange, 7a ... Seal ring holding part, 7b ... Spring holding part , 9: Rotating sealing ring, 9a: Rotating sealing end face, 10 ... Stationary sealing ring, 10a ... Stationary sealing end face, 11 ... Spring member, 12 ... Seal gas passage, 41 ... Sealing device (composite non-contact gas seal), 91 ... Dynamic pressure generating groove, 92 ... groove, 92a ... first groove portion, 92b ... second groove portion, 101 ... substrate, 102,102a, 102b, 102c ... glassy carbon layer, A ... treatment region, B ... in cover Area, G ... seal gas.

Claims (2)

A processing area in which the rotary table is disposed and a cover inner area between the rotary table and a cover that covers the rotary shaft and includes a non-metallic cover main body and a metal seal flange attached thereto. A sealing device provided to shield
A rotary seal ring concentric with the rotary shaft and fixed to the rotary table; a stationary seal ring held concentrically with the rotary shaft and opposed to the rotary seal ring in an axially movable manner on the seal flange ; A spring member that is disposed in the cover and presses and urges the stationary sealing ring to the rotating sealing ring, and penetrates through the cover body, the seal flange, and the stationary sealing ring, and opens between the sealing end faces that are the opposite end faces of both sealing rings. A series of sealing gas passages, and a sealing gas is ejected from the sealing gas passages between the sealing end faces so that the two regions are shielded and sealed while being kept in a non-contact state. was Ri Oh in a non-contact type mechanical seal,
A composite structure in which the stationary sealing ring is composed of a glassy carbon layer or a synthetic resin layer, including the inner peripheral surface layer of the sealing gas passage, in which the surface layer of the substrate is made of carbon and excluding the portion forming the sealed end face. Rotation characterized in that the part that contacts the seal gas and the part that faces the processing area in the seal flange is coated with fluororesin to prevent generation of particles due to contact with the seal gas. Sealing device for processing equipment that uses a table. A dynamic pressure generating groove is formed on the sealing end surface of one sealing ring, and in addition to the static pressure generated by the sealing gas between the sealing end surfaces, the dynamic pressure generated by the dynamic pressure generating groove is applied so that the sealing end surfaces are not in contact with each other. The sealing device for a processing apparatus using the rotary table according to claim 1, wherein the sealing device is configured to hold.

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