METHODS AND APPARATUS FOR PROCESSING A SUBSTRATE
Methods and apparatus for cleaning an edge of a substrate are provided. The invention includes a polishing film having a polishing side and a second side; an inflatable pad disposed adjacent the second side of the polishing film; a frame adapted to support the polishing film and the inflatable pad; and a substrate rotation driver adapted to rotate a substrate against the polishing side of the polishing film, wherein the polishing film is disposed between an edge of the substrate and the inflatable pad so that the inflatable pad and polishing film contour to the edge of the substrate with the polishing film contacting the edge of the substrate. Numerous other aspects are provided.
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This application is a division of, and claims priority to, U.S. Non-Provisional patent application Ser. No. 11/298,555, filed Dec. 9, 2005, and titled, “METHODS AND APPARATUS FOR PROCESSING A SUBSTRATE” (Attorney Docket No. 10414), which is hereby incorporated by reference herein in its entirety for all purposes.
CROSS-REFERENCE TO RELATED APPLICATIONSThe present invention is related to U.S. patent application Ser. No. 11/299,295 filed on Dec. 9, 2005 and entitled “METHODS AND APPARATUS FOR PROCESSING A SUBSTRATE” (Attorney Docket No. 10121) which is hereby incorporated herein by reference for all purposes.
FIELD OF THE INVENTIONThe present invention relates generally to substrate processing, and more particularly to methods and apparatus for cleaning an edge of a substrate.
BACKGROUND OF THE INVENTIONConventional systems, which contact a substrate edge with an abrasive film to clean the edge, may not thoroughly clean the edge. For example, the abrasive film may not sufficiently contact both bevels of the edge during cleaning. Additionally, the abrasive film may become worn from use, and therefore, lose its ability to sufficiently clean the substrate and require frequent replacement, which may affect semiconductor device manufacturing throughput. Accordingly improved methods and apparatus for cleaning an edge of a substrate are desired.
SUMMARY OF THE INVENTIONIn a first aspect of the invention, an apparatus adapted to polish an edge of a substrate includes a polishing film, a frame adapted to tension the polishing film so that at least a portion of the film is supported in a plane, and a substrate rotation driver adapted to rotate a substrate against the plane of the polishing film such that the polishing film is adapted to apply tension to the substrate, contour to an edge of the substrate which includes at least an outer edge and a first bevel, and polish the outer edge and the first bevel as the substrate is rotated.
In a second aspect of the invention an apparatus adapted to polish an edge of a substrate includes a plurality of polishing films, a frame adapted to tension each of the polishing films so that at least a portion of each of the films are supported in a respective plane, and a substrate rotation driver adapted to rotate a substrate against at least one of the respective planes of the polishing films such that any polishing films contacting the substrate apply pressure to the substrate, contour to an edge of the substrate, and polish the edge as the substrate is rotated.
In a third aspect of the invention an apparatus adapted to polish an edge of a substrate includes a polishing film having a polishing side and a second side, an inflatable pad disposed adjacent the second side of the polishing film, a frame adapted to support the polishing film and the inflatable pad, and a substrate rotation driver adapted to rotate a substrate against the polishing side of the polishing film. The polishing film is disposed between an edge of the substrate and the inflatable pad so that the inflatable pad and polishing film contour to the edge of the substrate and the polishing film contacts the edge of the substrate.
In a fourth aspect of the invention a method of cleaning an edge of a substrate includes (a) supporting a polishing film, (b) conforming the polishing film to an edge of a substrate, the edge including an outer edge and at least one bevel, and (c) rotating the substrate.
Other features and aspects of the present invention will become more fully apparent from the following detailed description, the appended claims and the accompanying drawings.
The present invention provides improved methods and apparatus for cleaning and/or polishing the edge of a substrate. With reference to
The present invention provides a frame for supporting a film (e.g., an abrasive polishing film) or abrasive buffer against the edge 104 of a substrate 100 as the substrate 100 is rotated (e.g., by a vacuum chuck, drive rollers, etc.). The film may be pressed against the rotating substrate edge 104 using a pad pushed by an actuator and/or an inflatable pad. In either case, the pad and/or inflatable pad may be soft and/or include or develop contours to conform with the shape of the substrate edge 104. Depending on the amount of force applied by the actuator, the resiliency of the pad selected, the amount of inflation of an inflatable pad, and/or the amount of tension on the film, a controlled amount of pressure may be applied to polish the edge 104. Alternatively or additionally, the film may be under tension within the frame such that the film itself is adapted to apply a variable amount of tension to the substrate edge 104 and to contour to both the outer edge 110 and at least one of the bevels 112, 114 (e.g., with or without additional support from a pad). Thus, the present invention provides precise control of an edge polish process which may be used to compensate for different edge geometries and changes in the substrate 100 as material is removed from the edge 104.
In some embodiments, the frame may support multiple heads, each head being adapted to support polishing film. The heads may support different types of films (e.g., films of different abrasive grits) which may be used concurrently, in a predefined sequence, or at different times. The heads may be disposed in different positions to allow the supported films to polish different portions of the edge 104 of the rotating substrate 100. The heads may be adapted to be moved (e.g., angularly translated about a tangential axis of the substrate 100 and/or circumferentially relative to the substrate 100) around the edge 104 by the frame so as to polish different portions of the edge 104. In some embodiments, the heads may continuously oscillate around the rotating edge 104 of the substrate 100. Each head may include an indexed spool of film and/or be contained in a replaceable cassette.
Additionally or alternatively, the present invention may include facilities to deliver fluids to the substrate edge 104 being polished. In some embodiments, one or more channels may be provided to direct chemicals or water to the substrate edge 104 to assist in the polishing and/or to wash away particles resulting from the polishing. The chemicals may be sprayed directly onto the substrate 100, at the substrate/polishing film interface, and/or may be applied to and/or through the film and/or pad. The fluids may be sprayed from either or both sides of the substrate 100 and the present invention may employ gravity or suction to cause the runoff not to contaminate or contact other parts of the substrate 100 or apparatus of the invention. Further, energy (e.g., megasonic energy) may be applied to the substrate edge 104 via fluid carrying such energy.
The substrate 100 may be rotated in a horizontal plane. In additional or alternative embodiments, the substrate 100 may be rotated in a vertical plane, other non-horizontal plane, and/or be moved between different planes of rotation.
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Additionally or alternatively, an additional length of the polishing film 204 may be supported and tensioned by spools 208, 210 mounted to the frame 202. A supply spool 208 may include unused polishing film 204 available to be unwound and pulled into position adjacent the substrate 100 while a take-up spool 210 may be adapted to receive used and/or worn polishing film 204. One or both of the spools 208, 210 may be indexed to precisely control the amount of polishing film 204 that is advanced. The polishing film 204 may be made from many different materials including aluminum oxide, silicon oxide, silicon carbide, etc. Other materials may also be used. In some embodiments, the abrasives used may range from about 0.5 microns up to about 3 microns in size although other sizes may be used. Different widths ranging from about 1 inch to about 1.5 inches may be used (although other widths may be used). In one or more embodiments, the polishing film may be about 0.002 to about 0.02 of an inch thick and be able to withstand about 1 to 5 lbs. of tension in embodiments that use a pad 206 and from about 3 to about 8 lbs. of tension in embodiments without a pad. Other films having different thicknesses and strengths may be used. The spools 208, 210 may be approximately 1 inch in diameter, hold about 500 inches of polishing film 204, and may be constructed from any practicable materials such as polyurethane, polyvinyl difluoride (PVDF), etc. Other materials may be used. The frame 202 may be constructed from any practicable materials such as aluminum, stainless steel, etc.
In some embodiments, one or more fluid channels 212 (e.g., a spray nozzle or bar) may be provided to deliver chemicals and/or water to aid in the polishing/cleaning of the substrate edge 104, lubricate the substrate, and/or to wash away removed material. The fluid channel 212 may be adapted to deliver fluid to the substrate 100, to the polishing film 204, and/or to the pad 206. The fluids may include deionized water which may serve as a lubricant and to flush particles away. A surfactant and/or other known cleaning chemistries may also be included. In some embodiments, sonic (e.g., megasonic) nozzles may be used to deliver sonicated fluids to the substrate edge 104 to supplement the cleaning. Fluid also may be delivered through the polishing film 204 and/or pad 206 to the edge 104.
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The drive rollers 408 and guide rollers 410 may include a groove that allows the rollers 408, 410 alone to support the substrate 100. In some embodiments the groove within the drive rollers 408 may have a diameter of approximately 2.5 inches and the groove within the guide rollers 410 may have a diameter of approximately 1 inch. Other dimensions are possible. The area of the drive rollers 408 in contact with the substrate 100 may include texturing or cross-grooves to allow the drive rollers 408 to grip the substrate 100. The drive rollers 408 and guide rollers 410 may be constructed from materials such as polyurethane, polyvinyl difluoride (PVDF), etc. Other materials may be used.
As shown in
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Additionally, the spools 208, 210 that are mounted to the head 504, may be driven by one or more drivers 604 (e.g., servo motors). The drivers 604 may provide both an indexing capability to allow a specific amount of unused polishing film 204 to be advanced or continuously fed to the substrate edge, and a tensioning capability to allow the polishing film to be stretched taught and to apply pressure to the substrate edge.
As can more clearly be seen in
Note that in the embodiment depicted in
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In yet another alternative embodiment, as shown in
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The pads 206, 206A, 206B may be made of material such as, for example, an acetal resin (e.g., Delrin® manufactured by DuPont Corporation), PVDF, polyurethane closed cell foam, silicon rubber, etc. Other materials may be used. Such materials may have a resilience or an ability to conform that is a function of the thickness or density of the pad. The material may be selected based upon its resilience. The desired resilience may be selected based upon the type of polishing required.
In some embodiments, the pad 206, 206A, 206B may have an adjustable amount of ability to conform to the substrate's edge. For example the pad 206, 206A, 206B may be or include an inflatable bladder such that by adding more air or liquid or other fluid, the pad becomes harder and by reducing the amount of air or liquid or other fluid in the bladder, the pad becomes more conforming.
In some embodiments, fluids used to aid in the polishing may be delivered to the substrate edge via the pads 206, 206A, 206B. A fluid channel may be provided to drip or spray the fluid on or into the pads. Alternatively, an inflatable pad may include a bladder with a semi-permeable membrane that allows fluid to be slowly released and transmitted to the polishing film 204 (e.g., through the pad). In such embodiments, the pads 206, 206A, 206B may be covered by, made of, and/or include material that absorbs and/or retains the fluids used (e.g., polyvinyl alcohol (PVA), etc.).
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After cleaning one or more substrates 100, the portion of the polishing film 204 employed for such cleaning may become worn. Therefore, the take-up reel 210 (
Regarding the example embodiment of an edge polishing apparatus 1300 of
In addition, a fluid supply 806 may be coupled to and under the control of the controller 1308. The fluid supply 806 may be controlled to independently deliver fluids (e.g., DI water, cleaning chemistry, sonicated fluids, gas, air, etc.) to each of the heads 1304 via one or more fluid channels 212. Under the direction of the controller 1308, various fluids may be selectively delivered to the pads 206, the polishing film 204, and/or the substrate edge 104 via the fluid channels 212. The fluid may be for use in polishing, lubricating, particle removal/rinsing, and/or inflating a bladder 802 (
The foregoing description discloses only exemplary embodiments of the invention. Modifications of the above disclosed apparatus and methods which fall within the scope of the invention will be readily apparent to those of ordinary skill in the art. For instance, although only examples of cleaning a round substrate are disclosed, the present invention could be modified to clean substrates having other shapes (e.g., a glass or polymer plate for flat panel displays). Further, although processing of a single substrate by the apparatus is shown above, in some embodiments, the apparatus may process a plurality of substrates concurrently.
Accordingly, while the present invention has been disclosed in connection with exemplary embodiments thereof, it should be understood that other embodiments may fall within the spirit and scope of the invention, as defined by the following claims.
Claims
1. An apparatus adapted to polish an edge of a substrate comprising:
- a polishing film having a polishing side and a second side;
- an inflatable pad disposed adjacent the second side of the polishing film;
- a frame adapted to support the polishing film and the inflatable pad; and
- a substrate rotation driver adapted to rotate a substrate against the polishing side of the polishing film,
- wherein the polishing film is disposed between an edge of the substrate and the inflatable pad so that the inflatable pad and polishing film contour to the edge of the substrate with the polishing film contacting the edge of the substrate.
2. The apparatus of claim 1 wherein the inflatable pad is selectively inflatable.
3. The apparatus of claim 2 wherein the edge of the substrate includes an outer edge and at least one bevel, and
- wherein the inflatable pad is adapted to inflate so that the inflatable pad and polishing film contour to the outer edge and the at least one bevel.
4. The apparatus of 3 wherein the inflatable pad is adapted to wrap around the outer edge and the at least one bevel.
5. The apparatus of claim 1 wherein the inflatable pad includes one or more inflatable bladders.
6. The apparatus of claim 2 wherein the edge of the substrate includes an outer edge, a first bevel, and a second bevel, and
- wherein the substrate includes a device region and an exclusion region, and
- wherein the inflatable pad is adapted to selectively inflate so that the inflatable pad and polishing film selectively contour to one or more of the outer edge, the first bevel, the second bevel, and the exclusion region.
7. The apparatus of claim 6 wherein the inflatable pad and polishing film are precluded from contacting the device region.
8. The apparatus of claim 1 wherein the polishing film, the inflatable pad, and the frame are contained in a replaceable cassette.
9. The apparatus of claim 1 wherein the frame is further adapted to angularly translate the polishing film around an axis tangential to the edge of the substrate.
10. The apparatus of claim 9 wherein the frame is further adapted to continuously oscillate about the edge of the substrate.
11. The apparatus of claim 1 wherein the frame is further adapted to circumferentially rotate, with respect to the substrate, the polishing film around the edge of the substrate.
12. The apparatus of claim 1 further comprising a fluid supply channel, and wherein the fluid supply channel is adapted to deliver at least one of water and a cleaning chemistry to the edge of the substrate.
13. The apparatus of claim 12 wherein the fluid supply channel is further adapted to deliver fluid to the edge of the substrate via the polishing film.
14. The apparatus of claim 12 wherein the fluid supply channel is further adapted to deliver fluid to the edge of the substrate via the inflatable pad.
15. The apparatus of claim 14 wherein the inflatable pad is permeable and inflatable with the fluid.
16. The apparatus of claim 12 wherein the fluid supply channel is adapted to deliver sonicated fluid to the edge of the substrate.
17. The apparatus of claim 1 wherein the polishing film is tensioned between a supply spool and a take-up spool.
18. The apparatus of claim 17 wherein the frame further comprises a polishing head.
19. The apparatus of claim 18 wherein the polishing head is adapted to support the polishing film tensioned between the supply spool and the take-up spool and the inflatable pad.
20. The apparatus of claim 1 wherein the polishing film is disposed one of orthogonally or longitudinally to the edge of the substrate.
Type: Application
Filed: Sep 26, 2008
Publication Date: Jan 15, 2009
Applicant: APPLIED MATERIALS, INC. (Santa Clara, CA)
Inventors: Gary C. Ettinger (Cupertino, CA), Erik C. Wasinger (Mountain View, CA), Sen-Hou Ko (Sunnyvale, CA), Wei-Yung Hsu (Santa Clara, CA), Liang-Yuh Chen (Foster City, CA), Ho Seon Shin (Cupertino, CA), Donald Olgado (Palo Alto, CA)
Application Number: 12/239,730