This application is based on and claims priority from Japanese Patent Application No. 2008-159034, filed on Jun. 18, 2008 with the Japanese Patent Office, the disclosure of which is incorporated herein in its entirety by reference.
The present invention relates to a substrate cleaning apparatus capable of brush-cleaning a periphery of a substrate.
A manufacturing process of a semiconductor device or Flat Panel Display (FPD) includes a cleaning process to remove particles or pollutants attached on a target object, such as semiconductor wafer or a glass substrate. As one example of a cleaning apparatus, there is a single-type cleaning apparatus. The single-type cleaning apparatus holds a substrate with a spin chuck and supplies cleaning liquid to a surface of a wafer while rotating the substrate so as to clean the surface of the wafer.
A chemical liquid of acid or alkali for cleaning liquid remains on a periphery of the substrate and dries to become extraneous matters (or sticked matter) during the cleaning process of the cleaning apparatus. Further, the materials removed through the cleaning process are re-attached onto the periphery of the substrate. Any process or apparatus was not suggested to treat the extraneous matters on the periphery of the substrate since the periphery of the substrate was not used as a commercial product. However, such extraneous matters affect a performance of a semiconductor device as the semiconductor device becomes finer, because the extraneous matters that are formed on the periphery of the substrate are attached on a substrate supporting arm of a substrate transfer device. Accordingly, it has been suggested a technology of removing the extraneous matters on a periphery of the substrate by contacting a sponge-type brush with the periphery of the substrate. Examples of such technology are disclosed in Japanese Utility Model Laid-open Publication Hei 5-79939 and Japanese Patent Laid-open Publication No. 2007-165794.
However, a brush-cleaning process of extraneous matters is not easily performed when the extraneous matters are firmly attached to a periphery of a substrate. A bevel of the periphery of the substrate further makes the brush-cleaning process difficult. Particularly, because the periphery of the substrate (for example, a semiconductor wafer) has surfaces that are diametrically opposite, a cleaning performance of a sponge-type brush is different for the surfaces. Thus, the extraneous matters cannot be efficiently removed by simply contacting the sponge-type brush with the slanted periphery of the substrate.
In accordance with one embodiment, a substrate cleaning apparatus is provided. The substrate cleaning apparatus includes a substrate holding device to rotatably hold a substrate, a substrate rotation device to rotate the substrate held by the substrate holding device, a cleaning liquid supplying device to supply cleaning liquid to the substrate held by the substrate holding device, and a cleaning device including a brush and a pressing device, the brush including a periphery cleaning part in contact with a periphery of the substrate during cleaning of the substrate, the pressing device pushing the periphery cleaning part to the periphery of the substrate. The periphery cleaning part includes a changing part, and the property of the changing part changes along a diameter of the periphery cleaning part to distribute cleaning performance along the diameter.
The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.
In the following detailed description, reference is made to the accompanying drawing, which form a part hereof. The illustrative embodiments described in the detailed description, drawing, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented here.
The present invention provides a substrate cleaning apparatus capable of efficiently removing extraneous matters attached on a periphery of a substrate with a brush.
In accordance with one embodiment, a substrate cleaning apparatus is provided. The substrate cleaning apparatus includes a substrate holding device to rotatably hold a substrate, a substrate rotation device to rotate the substrate held by the substrate holding device, a cleaning liquid supplying device to supply cleaning liquid to the substrate held by the substrate holding device, and a cleaning device including a brush and a pressing device. The brush includes a periphery cleaning part in contact with a periphery of the substrate during cleaning of the substrate. The pressing device pushes the periphery cleaning part to the periphery of the substrate. The periphery cleaning part includes a changing part, and a property of the changing part changes along a diameter of the periphery cleaning part to distribute cleaning performance along the diameter.
At least one of height, shape, hardness, and material of the changing part may be changed along the diameter of the periphery cleaning part. The changing part may be divided into a plurality of parts along the diameter of the periphery cleaning part. At least one of height, shape, hardness, and material of the plurality of parts may be different between the adjacent parts.
The cleaning device may further include a brush rotating device to rotate the brush. The brush rotating device may rotate the brush and the pressing device may push the periphery cleaning part to the periphery of the substrate, thereby cleaning the periphery of the substrate. The periphery cleaning part may be divided into a plurality of brush parts along a circumferential direction. Properties between the adjacent brush parts may be different, and at least one of the brush parts may function as the changing part.
The periphery cleaning part may be supported by a brush supporting member.
The brush may be integrally and coaxially formed with the periphery cleaning part and may include an end surface cleaning part to be in contact with an end surface of the substrate. The end surface cleaning part may be formed with a sponge-type resin, and the pressing device may push the end surface cleaning part to the end surface of the substrate.
According to some embodiments, when cleaning the periphery of the substrate while being in contact with the brush, the property of the periphery cleaning part of the brush is changed along the diameter of the periphery cleaning part to distribute the cleaning performance in a diametrical direction of the periphery cleaning part. Therefore, an efficient removing of extraneous matters can be achieved even in the case that the property of the substrate is different along a diameter of the substrate. Thus, the efficient removing of the extraneous matters at a bevel of a semiconductor wafer can be achieved.
A substrate cleaning apparatus 1 includes a chamber 2, and chamber 2 includes a spin chuck 3 on chamber 2. Spin chuck 3 holds a target object, for example, a semiconductor wafer W (hereinafter “wafer W”) in a horizontal state through vacuum absorbing. Spin chuck 3 is configured to rotate by a motor 4 that is provided on a lower side of chamber 2 through an axis 3a. Further, a cup 5 is provided within chamber 2 to cover wafer W held by spin chuck 3. A gas/liquid discharge pipe 6 is provided on a bottom part of cup 5 to discharge gas and liquid, and extends toward a downside of chamber 2. A loading/unloading port 7 is formed on a side wall of chamber 2 to load/unload wafer W. Further, a fluid seal 8 is provided between axis 3a and bottom parts of cup 5 and chamber 2.
Further, substrate cleaning apparatus 1 may further include a cleaning liquid supplying device 10 to supply cleaning liquid, and a cleaning device 20 to clean a periphery of wafer W with a brush.
Cleaning liquid supplying device 10 includes an upper surface-side cleaning liquid nozzle 11a provided on an upper surface of cup 5 and a rear surface-side liquid nozzle 11b provided on a rear surface of wafer W held by spin chuck 3. Upper surface-side cleaning liquid nozzle 11a and rear surface-side liquid nozzle 11b are connected with one ends of a surface-side cleaning liquid supplying pipe 13a and a rear surface-side liquid supplying pipe 13b, respectively. The other ends of both surface-side cleaning liquid supplying pipe 13a and rear surface-side liquid supplying pipe 13b are commonly connected to a cleaning liquid source 12. Upper surface-side cleaning liquid nozzle 11a supplies the cleaning liquid from cleaning liquid source 12 to an area near a center of a surface of wafer W through upper surface-side cleaning liquid supplying pipe 13a, and rear surface-side liquid nozzle 11b supplies the cleaning liquid from cleaning liquid source 12 to rear surface of wafer W through rear surface-side liquid supplying pipe 13b. Upper surface-side cleaning liquid supplying pipe 13a and rear surface-side liquid supplying pipe 13b include valves 14a and 14b, respectively. Deionized water or chemical liquid can be used as the cleaning liquid.
Cleaning device 20 includes a brush 21 to clean the periphery and an end surface of wafer W, a rotation supporting member 22 configured to rotatably support brush 21, a rotating arm 25 to rotate brush 21, a shaft part 26 including a rotating shaft that is a rotation axis of rotating arm 25, a rotating device to rotate the rotating shaft so as to rotate rotating arm 25, and a rotating/lifting part 27 including a lifting device that lifts rotating arm 25. Brush 21 is supported by a brush supporting member 23 at a lower side of brush 21.
Rotating arm 25 has an angled pipe-like shape that extends in a horizontal direction and rotation supporting member 22 is rotatably provided on a leading end of rotating arm 25. Rotation supporting member 22 is rotatably supported by a pair of bearings 31a and 31b which is attached to rotating arm 25. A pulley 32 is exteriorly fitted with a center of the rotation supporting member 22, and a belt 33 is wound around pulley 32. Belt 33 extends horizontally in an inner space of rotating arm 25. A motor 34 for brush rotation is provided in rotating arm 25, and is fixed to a bottom surface of rotating arm 25. A rotation axis 34a of motor 34 for brush rotation is attached with pulley 35, and belt 33 is wound around pulley 35. Therefore, rotation supporting member 22 is rotated through belt 33 by the operation of motor 34, and brush 21 is rotate together with rotation supporting member 22.
A vertically extending rotating shaft 38 is fixed to a base end of rotating arm 25 by a pair of fixing members 39 each provided on upper and lower portions inside rotating arm 25. Rotating shaft 38 passes through shaft part 26, and extends up to rotating/lifting part 27.
Rotating/lifting part 27 includes a case 41 extending downwardly from shaft part 26, and a rotating device 42 and lifting device 45 provided within case 41. Rotating device 42 includes a motor 43 for rotation. A rotation axis of motor 43 for rotation is connected with a lower end of rotating shaft 38, so that rotating arm 25 fixed to rotating shaft 38 can be rotated through the operation of motor 43 for rotation. Further, lifting device 45 includes a supporting member 46 to rotatably support rotating shaft 38 through a bearing 47, a ball screw 48 vertically extending from a bottom plate of case 41 to screw into supporting member 46, a motor 49 for lifting fixed to a bottom plate of case 41 to rotate ball screw 48, and a guide member 50 vertically provided inside case 41 to guide supporting member 46. Lifting device 45 lifts rotating shaft 38 through a ball screw device so as to lift rotating arm 25 together with rotating shaft 38. Further, rotating arm 25 is rotated through rotating device 42 and is lifted through lifting device 45 so as to press brush 21 toward a periphery of wafer W with a desired pressure. Rotating device 42 and lifting device 45 function as a pressing device of brush 21.
Periphery cleaning part 21c has a changing part 52 on which a property of periphery cleaning part 21c is changed along a diameter of periphery cleaning part 21c to distribute cleaning liquid along the diameter. Periphery cleaning part 21c, as depicted in
Further, as shown in
Further, changing part 52 of brush 21 can be formed in such a manner that periphery cleaning part 21c has a different shape along the diameter of periphery cleaning part 21c. For example, changing part 52 of brush 21 can be formed in such as matter that periphery cleaning part 21c has protrusions 53 on its surface and the number of protrusions 53 is increased as it goes toward the inner side of brush 21, as shown in
Furthermore, as shown in
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Brush 21 can be attached to brush supporting member 23 with an adhesive. If periphery cleaning part 21c of brush 21 is divided into a plurality of parts, as shown in
End-surface cleaning part 21b of brush 21 can be formed with a sponge-type resin.
The sponge-type resin used for end-surface cleaning part 21b and periphery cleaning part 21c of brush 21 can include polyvinyl alcohol (PVA). In some embodiments, polyethylene (PE) can be used for the resin of brush 21. Further, the resin of the toothbrush-type bristle assembly used for periphery cleaning part 21c can include polypropylene. Brush supporting member 23 may be formed with a resin. For example, a hard resin, such as polyether ether ketone (PEEK), polyethylene terephthalate (PET, or polyvinyl chloride (PVC) may be used for brush 21 to prevent from deformation of brush 21.
As shown in
Hereinafter, a cleaning process of wafer W by substrate cleaning apparatus 1 will be described.
Brush 21 is attached to rotation supporting member 22. Then, wafer W is loaded into chamber 2 in a state where brush 21 is placed back to an exterior side of wafer W, and wafer W is held onto spin chuck 3. When brush 21 is placed back, cleaning liquid is supplied to brush 21 to prevent brush 21 from drying. In this state, motor 4 is operated so as to rotate wafer W together with spin chuck 3 in a predetermined number of rotations, and brush 21 is rotated with brush supporting member 22 by motor 34 for brush rotation while supplying the cleaning liquid from cleaning liquid nozzle 11 to wafer W.
Then, rotating arm 25 is rotated toward wafer W held on spin chuck 3 by rotating device 42 so as to push a circumference (which has a small diameter) of end-surface cleaning part 21b of brush 21 to an end surface of wafer W with a predetermined pressure power. A height of rotating arm 25 is adjusted by lifting device 45 so as to push an upper surface (which has a large diameter) of periphery cleaning part 21c of brush 21 to a periphery of a rear surface of wafer W with a predetermined pressure power. As a result, a brush cleaning is started.
In some embodiments, appropriate brush 21 can be selected considering a shape of wafer W and attached condition of extraneous matters. For examples, because the shape of wafer W and the attached condition of the extraneous matters are different along a diameter of the periphery of wafer W, it is necessary to adjust a cleaning performance along the diameter of the periphery of wafer W. In order to adjust the cleaning performance, changing part 52 of periphery cleaning part 21c can be used. For example, since properties of changing part 52 can be changed along the diameter of periphery cleaning part 21c, the cleaning performance can be adjusted along the diameter in order to distribute the cleaning performance in the diametrical direction of wafer W. For example, as shown in
In illustrated embodiment of
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In illustrated embodiment of
In illustrated embodiment of
As illustrated in
As illustrated in
As illustrated in
When periphery cleaning part 21c, as illustrated in
The present invention is not limited to the above embodiments, but can be variously modified. For example, although it is illustrated that an end surface and a periphery of a rear surface of a wafer are cleaned using a brush in which an upper part of the brush is for cleaning the end-surface of the wafer and a lower part of the brush is for cleaning the periphery of the rear surface of the wafer, the end surface and the periphery of the rear surface of the wafer can be cleaned by using a brush 21′, as illustrated in
Further, the periphery of the rear surface of wafer W may be cleaned with an upper side of a brush 21″ which has a disc-liked shape as shown in the diagram (a) of
Still further, although the above embodiments are illustrated to achieve efficient cleaning the bevel of the wafer by distributing a cleaning performance, the present invention is not limited thereto. For example, various distributions can be achieved according to the cleaning performance distribution required along the diameter of the periphery of the wafer.
Still further, the shape of the brush is not limited to the above embodiments, but can be formed in various shapes.
Still further, although the above embodiments are illustrate to have the cleaning device to clean the end surface of the wafer and the periphery of the rear surface of the wafer, a cleaning device to clean a surface of the wafer may be provided. Further, the present invention is not limited to the apparatus of the embodiment, but can be applied to the cleaning apparatus to clean the surface/rear surface of the wafer or the apparatus to clean the rear surface of the wafer.
Still further, although a semiconductor wafer is used as a target substrate in the above illustrated embodiment, the present invention is not limited thereto. By way of example of other target substrate, there can be a glass substrate for a liquid crystal display device, for example, a substrate for a flat panel display device.
From the foregoing, it will be appreciated that various embodiments of the present disclosure have been described herein for purposes of illustration, and that various modifications may be made without departing from the scope and spirit of the present disclosure. Accordingly, the various embodiments disclosed herein are not intended to be limiting, with the true scope and spirit being indicated by the following claims.
Number | Date | Country | Kind |
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2008-159034 | Jun 2008 | JP | national |