JP4361344B2 - Seal structure for substrate processing apparatus and substrate processing apparatus - Google Patents

Description

  According to the present invention, a frame having a sealing member made of an elastic material is placed on a substrate to be processed, and a processing liquid is supplied to a space formed by the surface of the substrate and the inner wall surface of the frame. The present invention relates to a seal structure between a frame body and a substrate of a substrate processing apparatus for processing a substrate.

  2. Description of the Related Art In recent years, in the manufacturing process of semiconductor elements and FPDs (Flat panel displays), various ingenuity has been made to achieve miniaturization of wiring and improve yield. For example, in a wet process such as CMP (Chemical Mechanical Polishing), various types of cleaning, coater & developer, etching, electrolytic plating, etc., a substrate such as a semiconductor wafer or a glass substrate for FPD and various chemical solutions Various controls have been devised, such as the liquid contact method, chemical supply method, and substrate movement, and this has become the know-how of each device manufacturer.

  In the wet process, as schematically shown in a sectional view in FIG. 5, a cylindrical (semiconductor wafer) or rectangular (FPD glass) frame 10 having an O-ring 5 made of an elastic material on the lower end surface 10b. Is placed on the substrate 4, the frame body 10 is pressed toward the substrate, and the O-ring 5 is brought into close contact with the peripheral edge of the substrate 4 to form a space between the surface of the substrate 4 and the inner wall surface 10 a of the frame body 10. The surface of the substrate 4 is treated by injecting a chemical solution L into this space (see, for example, Patent Documents 1 to 4).

JP-A-6-117996 JP-A-7-99342 Japanese Patent Laid-Open No. 11-24615 JP 2003-55797 A

  In the seal structure including the substrate 4 and the O-ring 5 described in Patent Document 1, since the O-ring 5 is fitted into the dovetail groove 6 provided on the lower end surface 10b of the frame body 10, as shown in FIG. A minute gap C is formed between the substrate 4, the O-ring 5, and the lower end surface 10 on the inner wall side 10 a of the frame 10, and the chemical solution L enters the minute gap C. In the wet process, the type of the chemical solution L is often changed and processed multiple times. In that case, the processed chemical solution L is removed while maintaining the sealing structure formed by the substrate 4 and the O-ring 5 shown in the figure. And after washing | cleaning the inner wall face 10a of the frame 10, inject | pouring new chemical | medical solution L is performed. Therefore, if the chemical liquid L used in the previous process remains in the minute gap C, the chemical liquid L used in the new process may be mixed and adversely affected.

  The chemical liquid L remaining in the minute gap C may be removed or wiped off by centrifugal force, but the chemical liquid L that has entered the minute gap C is difficult to be discharged due to surface tension and is difficult to remove completely. Moreover, depending on the case, the chemical | medical solution L may have penetrate | invaded also into the inside of the dovetail groove 6 of the frame 10, and removal of a residual liquid is made still more difficult.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a sealing structure that hardly causes chemical liquid residue and a substrate processing apparatus that can stably perform processing using the chemical liquid.

In order to achieve the above object, the present invention provides the following sealing structure for a substrate processing apparatus and substrate processing apparatus.
(1) A substrate having a sealing member made of an elastic material at the lower end is placed on a substrate to be processed, and a processing liquid is supplied to a space formed by the surface of the substrate and the inner wall surface of the frame. A seal structure between a frame body and a substrate of a substrate processing apparatus that performs the process of
The frame is formed with a fitting groove that opens at a predetermined width over the entire circumference of the inner wall surface at a predetermined height from the lower surface facing the substrate, and the inner wall surface on the lower surface side of the fitting groove is a sealing member A space for storing the seal member that is retreated by the thickness of the seal portion and has a substantially L-shaped cross section is formed,
The seal member includes a seal portion having a predetermined thickness that forms an inner wall surface, and a fitting portion that is bent outwardly perpendicularly from the upper end portion of the seal portion and is fitted into the fitting groove of the frame body. A base portion formed in a thickness that can be inserted into the fitting groove of the frame body, and a base portion and a fitting groove between the base body and the base portion provided in a linear manner on the upper surface of the base portion. It is formed with a protrusion with a height that closes the gap between
The substrate processing is characterized in that the fitting portion of the seal member is inserted into the fitting groove of the frame body, and the inner wall surface continuous with the same inner diameter to the substrate is formed by the inner wall surface of the frame body and the seal surface of the seal member. Seal structure for equipment.
(2) The opening width of the fitting groove of the frame is 80 to 98% of the total thickness of the base portion of the seal member and the height of the protrusion, and the depth from the receding end surface of the inner wall surface is the seal of the seal member The sealing structure for a substrate processing apparatus according to (1) , wherein the thickness is 120 to 300% of the thickness of the portion .
(3) The sealing member is a rubber made of vinylidene fluoride / hexafluoropropylene copolymer, vinylidene fluoride / hexafluoropropylene / tetrafluoroethylene copolymer, or tetrafluoroethylene / propylene / vinylidene fluoride copolymer. The sealing structure for a substrate processing apparatus according to the above (1) or (2), comprising a rubber composition as a component .
(4) A substrate having a sealing member made of an elastic material at the lower end is placed on the substrate to be processed, and the processing liquid is supplied to the space formed by the surface of the substrate and the inner wall surface of the frame. A substrate processing apparatus for performing
A substrate processing apparatus characterized in that a gap between the substrate and the frame is sealed by the seal structure described in any one of (1) to (3) above .

  According to the sealing structure for a substrate processing apparatus of the present invention, since there is no step between the inner wall surface 10a of the frame 4 and the inner wall surface 3a of the sealing member 3, a single inner wall surface is formed. Thus, the minute gap C is not formed between the lower end surface 10b of the frame 10, the seal member 3 and the substrate 4, and the used chemical solution L can be completely removed, and the treatment with the new chemical solution L is stabilized. Can be done. As a result, a high-quality substrate can be produced with a high yield.

  Hereinafter, the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a cross-sectional view showing a seal member A constituting one embodiment of a seal structure for a substrate processing apparatus of the present invention, FIG. 2 is a cross-sectional view showing a frame 10, and FIG. It is sectional drawing which shows the state which constructed | assembled the sealing structure.

  As shown in FIG. 1, the seal member A includes a seal portion 3 formed in a frame shape such as a circle (semiconductor wafer) or a rectangle (FPD glass) according to the planar shape of the substrate 4, and an outer side of the seal portion 3. It has a substantially inverted L-shaped cross-sectional shape consisting of a fitting portion 2 that bends in a straight line. The inner diameter of the inner wall surface 3 a of the seal portion 3 is defined to be the same as the inner diameter of the inner wall surface 10 a of the frame body 10. Further, as shown in FIG. 3, the hanging length of the seal portion 3 is defined so that the lower end portion 3 b protrudes from the lower end surface 10 b of the frame body 10 when attached to the frame body 10.

  The fitting part 2 is comprised from the base 2a inserted in the fitting groove B of the frame 10, and the protrusion 1 formed in the upper surface of the base 2a around the line. The protrusion amount (height) of the protrusion 1 is defined to be larger than the opening width (t2) of the fitting groove B of the frame body 10 in total (t1) with the thickness of the base portion 2a. The number of the protrusions 1 is not limited, but by providing a plurality of protrusions 1 in parallel as shown in the drawing, when being inserted into the fitting grooves B of the frame body 10, the load is distributed in a well-balanced manner to improve the sealing performance. Will be able to. Moreover, although the protrusion 1 can also be made independent, in that case, by forming directly on the seal part 3 as shown in the figure, it is possible to efficiently receive a load and improve the sealing performance, which is preferable. . For the same reason, when a plurality of protrusions 1 are formed, one of them is preferably formed immediately above the seal portion 3. Furthermore, the cross-sectional shape of the protrusion 1 may be a semicircle, a triangle, a waveform, or the like in addition to the substantially rectangular shape illustrated.

  On the other hand, the frame 10 is formed in a frame shape such as a circle (semiconductor wafer) or a rectangle (FPD glass) according to the planar shape of the substrate 4. Further, as shown in FIG. 2, a fitting groove B into which the fitting portion 2 of the seal member A is fitted over the entire circumference of the inner wall surface 10a is formed at a predetermined height from the lower end surface 10b facing the substrate. Further, on the lower end surface 10e side of the fitting groove 10B, the inner wall surface 10a retreats by the thickness (w) of the seal portion 3 of the seal member A to form a receding end surface 10d. A vacant space is formed.

  Therefore, by fitting the fitting portion 2 of the seal member A into the fitting groove B of the frame body 10 and accommodating the entire seal member A in the space of the frame body 1, as shown in FIG. The inner wall surface 10a and the inner wall surface 3a of the seal member A form a surface that continues to the substrate 4 without any step. When the frame body 10 is placed on the substrate 4 and pressed, a seal structure is formed between the lower end 3b of the seal portion 3 of the seal member A and the substrate 4. 5) There is no minute gap C formed by the substrate 4, the seal portion 3, and the lower end surface 10b of the frame body 10, and the chemical liquid L does not remain.

  Further, the protrusion 1 of the fitting portion 2 of the seal member A presses the upper wall surface 10c of the fitting groove B of the frame body 10 to close the gap between the sealing member A and the fitting groove B of the frame body 10, The chemical solution L is prevented from entering and remaining at the joint between the inner wall surface 3a of the seal member A and the inner wall surface 10a of the frame 10. In order to further improve the sealing performance at the joint between the inner wall surface 3a of the seal member A and the inner wall surface 10a of the frame body 10, the opening width (t2) of the fitting portion B of the frame body 10 is set to the fit of the seal member A. 80 to 98%, particularly 90 to 95% of the total length (t1) of the thickness of the base portion 2a of the joint portion 2 and the height of the protruding portion 1, and from the depth of the fitting portion B of the frame body 10, that is, from the receding end surface 10d. The distance (d) to the end face 10f of the fitting part B is preferably 120 to 300%, particularly 150 to 250% of the thickness (w) of the seal part 3 of the seal member A. When the opening width (t2) of the fitting groove B of the frame body 10 exceeds 98% of the total length (t1) of the fitting portion 2 of the seal member A, the chemical liquid L easily enters the fitting groove B. If it is less than 80%, the fitting portion 2 of the seal member A extends in the radial direction (left and right direction on the paper surface) and the seal line is swelled, so that sufficient sealability cannot be obtained. Further, when the depth (d) of the fitting groove B of the frame body 10 exceeds 300% of the thickness (w) of the seal portion 3 of the seal member A, the mountability is deteriorated, and an effect of providing a simple structure is provided. If the ratio is less than 120%, the seal portion 3 is deformed by a load, and the fitting portion 2 of the seal member A is likely to be pushed out from the fitting groove B of the frame body 10, which is not preferable in terms of reliability.

  There is no restriction | limiting in the forming material of the sealing member A and the frame 10, According to the kind of chemical | medical solution L to be used, it can select suitably. Specifically, as the material for forming the seal member A, fluorine-based elastomer, ethylene propylene rubber, nitrile rubber, butyl rubber, chloroprene rubber, silicone rubber, or the like can be appropriately selected and used. However, since the chemical solution L for treating the semiconductor wafer or the FPD glass substrate as the substrate 4 is often strongly acidic or strongly basic, the sealing member A is preferably excellent in acid resistance and alkali resistance. It is preferable to make it the rubber composition containing. Conventionally known fluorine-based elastomers can be widely used. For example, vinylidene fluoride / hexafluoropropylene-based copolymers (for example, DuPont Viton A, Daikin Industries Daiel, Dainion Florel, and Augmont Techno) Fluorocarbons etc. are available from the market), vinylidene fluoride / hexafluoropropylene / tetrafluoroethylene copolymers (eg DuPont Viton B, Daikin Industries Daiel, Dainion Florel, Augmont technofuron, etc.) Possible), tetrafluoroethylene / propylene / vinylidene fluoride copolymer (for example, Asahi Glass Aflas is available from the market) and the like can be suitably used. Among these, vinylidene fluoride / hexafluoropropylene copolymer or vinylidene fluoride / hexafluoropropylene / tetrafluoroethylene copolymer is particularly preferable.

  Various additives can be blended with each of the above rubber materials in order to reinforce and improve properties. Especially, it is preferable to mix | blend a filler and a reinforcing fiber. As fillers, inorganic fillers such as carbon black, barium sulfate, titanium oxide, aluminum oxide, calcium carbonate, calcium silicate, magnesium silicate, aluminum silicate, polytetrafluoroethylene resin, polyethylene resin, polypropylene resin, phenol Organic fillers such as resins, polyimide resins, melamine resins, and silicone resins can be mentioned, but are not limited thereto. It is also possible to use a plurality of fillers in combination.

  As reinforcing fibers, glass fibers, alumina fibers, rock wool and other inorganic fibers, cotton, wool, silk, hemp, nylon fibers, aramid fibers, vinylon fibers, polyester fibers, rayon fibers, acetate fibers, phenol-formaldehyde fibers, Examples include, but are not limited to, organic fibers such as polyphenylene sulfide fibers, acrylic fibers, polyvinyl chloride fibers, polyvinylidene chloride fibers, polyurethane fibers, and polytetrafluoroethylene fibers. It is also possible to use a plurality of fibers in combination.

  In addition, a crosslinking additive for a fluorine-based elastomer can be blended.

  For the sealing member A, for example, a fluorine-based elastomer is kneaded with a kneader such as a biaxial roll, kneader, Banbury mixer, etc., and a filler or reinforcing fiber is added thereto under kneading, and finally a crosslinking system is added. A fluororubber composition is prepared by adding an agent, and after aging as necessary, it is molded into the above-mentioned shape by an ordinary heat molding method. In the thermoforming method, a fluoro rubber composition is filled into a mold having a predetermined shape and heated and pressed, and then secondary crosslinking is performed in a hot air flow at 150 ° C. to 300 ° C., preferably 200 ° C. to 250 ° C.

  Moreover, it is preferable that the frame 10 is also excellent in acid resistance and alkali resistance, and can be produced with fluorine resin or ceramics.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to a following example at all.

(Example 1)
Each material shown below was kneaded according to a conventional method and aged overnight to obtain a fluoro rubber composition. Then, using a mold having a mirror surface, heat press and hold at 170 ° C. for 10 minutes to crosslink, further gear open at 230 ° C. for 24 hours, and the cross-sectional shape shown in FIG. An annular seal member A having an inner diameter of 100 mm was produced.
Fluoro rubber (DuPont Viton A) 100 parts by weight Carbon black 30 parts by weight Magnesium oxide 5 parts by weight Calcium hydroxide 3 parts by weight Crosslinking accelerator ( Phosphonium-based) ... 4 parts by weight Crosslinking agent (polyol-based) 1.5 parts by weight

  Then, the obtained seal member A was attached to an annular PTFE resin frame 10 having an inner diameter of 100 mm and a cross-sectional shape shown in FIG. The opening width (t2) of the fitting groove B of the frame 10 is 90% of the total length (t1) of the mating portion 2 of the seal member A, and the depth (d) of the fitting groove B of the frame 10 is set. The thickness (w) of the seal portion 3 of the seal member A was set to 200%.

(Comparative Example 1)
An O-ring having a diameter of 2.62 mm and an inner diameter of 101 mm was molded using the above fluororubber composition, and was mounted on a PTFE resin frame 10 having an inner diameter of 100 mm and having a dovetail groove 6 shown in FIG.

(Seal performance evaluation)
As shown in FIG. 4, the frame with a seal member produced in Example 1 or the frame 7 with an O-ring produced in Comparative Example 1 was placed on a semiconductor wafer 8 and fixed with a load of a linear pressure of 2 N / mm. . Thereafter, as a simple evaluation method, 1 liter of hydrogen fluoride is added as a chemical solution to the space formed by the frame and the semiconductor wafer 8, and after 1 minute, a tank formed by the frame and the semiconductor wafer 8 is formed. Tilt and discharged. Thereafter, 1 liter of ultrapure water having a conductivity of 0.055 μS / cm was added as a cleaning liquid in the same space, and the conductivity of the cleaning liquid at that time was measured. And washing | cleaning was repeated until the electrical conductivity of the washing | cleaning liquid became 0.5 microsiemens / cm or less, and the grade of the chemical | medical solution residue was confirmed. As a result, in the frame with a seal member produced in Example 1, the conductivity of the cleaning liquid becomes 0.5 μS / cm or less after 10 washings, whereas in the frame with an O-ring produced in Comparative Example 1, 20 is obtained. Even after the second washing, the target conductivity could not be obtained.

It is sectional drawing which shows the sealing member which comprises one Embodiment of the sealing structure for substrate processing apparatuses of this invention. It is sectional drawing which shows the frame which comprises one Embodiment of the sealing structure for substrate processing apparatuses of this invention. It is sectional drawing which shows typically one Embodiment of the sealing structure for substrate processing apparatuses of this invention. It is a side view for demonstrating the evaluation method of seal performance evaluation in an Example. It is sectional drawing which shows typically an example of the sealing structure for substrate processing apparatuses using the conventional O-ring.

Explanation of symbols

A Seal member 1 Protruding portion 2 Joint portion 3 Seal portion w Seal portion thickness B Fitting groove t1 Fitting groove opening width d Fitting groove depth 4 Substrate 5 O-ring 6 Dovetail groove C Clearance 10 Frame body L Liquid chemical

Claims (4)

A substrate having a sealing member made of an elastic material at the lower end is placed on the substrate to be processed, and a processing liquid is supplied to a space formed by the surface of the substrate and the inner wall surface of the frame to process the substrate. A sealing structure between a frame of a substrate processing apparatus to be performed and a substrate,
The frame is formed with a fitting groove that opens at a predetermined width over the entire circumference of the inner wall surface at a predetermined height from the lower surface facing the substrate, and the inner wall surface on the lower surface side of the fitting groove is a sealing member A space for storing the seal member that is retreated by the thickness of the seal portion and has a substantially L-shaped cross section is formed,
The seal member includes a seal portion having a predetermined thickness that forms an inner wall surface, and a fitting portion that is bent outwardly perpendicularly from the upper end portion of the seal portion and is fitted into the fitting groove of the frame body. A base portion formed in a thickness that can be inserted into the fitting groove of the frame body, and a base portion and a fitting groove between the base body and the base portion provided in a linear manner on the upper surface of the base portion. It is formed with a protrusion with a height that closes the gap between
The substrate processing is characterized in that the fitting portion of the seal member is inserted into the fitting groove of the frame body, and the inner wall surface continuous with the same inner diameter to the substrate is formed by the inner wall surface of the frame body and the seal surface of the seal member. Seal structure for equipment. The opening width of the fitting groove of the frame is 80 to 98% of the total thickness of the base portion of the seal member and the height of the protrusion, and the depth from the receding end surface of the inner wall surface is the thickness of the seal portion of the seal member 2. The sealing structure for a substrate processing apparatus according to claim 1, wherein the sealing structure is 120 to 300% of the thickness . The seal member is a vinylidene fluoride / hexafluoropropylene copolymer, a vinylidene fluoride / hexafluoropropylene / tetrafluoroethylene copolymer, or a tetrafluoroethylene / propylene / vinylidene fluoride copolymer. The seal structure for a substrate processing apparatus according to claim 1 or 2, comprising a rubber composition . A substrate having a sealing member made of an elastic material at the lower end is placed on the substrate to be processed, and a processing liquid is supplied to a space formed by the surface of the substrate and the inner wall surface of the frame to process the substrate. A substrate processing apparatus to perform,
A substrate processing apparatus , wherein a gap between the substrate and the frame is sealed by the seal structure according to any one of claims 1 to 3 .

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