METHODS AND APPARATUS FOR CLEANING A SUBSTRATE EDGE USING CHEMICAL AND MECHANICAL POLISHING
Methods and apparatus are provided for concurrently chemically and mechanically polishing a substrate edge. The invention includes a substrate support adapted to rotate a substrate; a polishing head adapted to contact an edge of the substrate, the polishing head including a first channel adapted to apply a first fluid to the edge of the substrate; a second channel adapted to direct a second fluid onto a major surface of the rotating substrate; and a third channel adapted to direct a third fluid at the major surface of the substrate and to prevent the second fluid from diluting the first fluid. Numerous other aspects are provided.
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The present application claims priority from U.S. Provisional Patent Application Ser. No. 60/892,237 filed Feb. 28, 2007, entitled “SUBSTRATE EDGE BEVEL POLISHING SYSTEMS AND METHODS USING CHEMICALS FOR MATERIAL REMOVAL” (Attorney Docket No. 11445/L).
CROSS-REFERENCE TO RELATED APPLICATIONSThe present application is also related to the following commonly-assigned, co-pending U.S. patent applications, each of which is hereby incorporated herein by reference in its entirety for all purposes:
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);
U.S. patent application Ser. No. 11/298,555 filed on Dec. 9, 2005 and entitled “METHODS AND APPARATUS FOR PROCESSING A SUBSTRATE” (Attorney Docket No. 10414);
U.S. patent application Ser. No. 11/693,695 filed on Mar. 29, 2007 and entitled “METHODS AND APPARATUS FOR POLISHING AN EDGE OF A SUBSTRATE” (Attorney Docket No. 10560);
U.S. Patent Application Ser. No. 60/939,351, filed May 21, 2007, entitled “METHODS AND APPARATUS FOR POLISHING A NOTCH OF A SUBSTRATE USING AN INFLATABLE POLISHING WHEEL” (Attorney Docket No. 10674/L);
U.S. Patent Application Ser. No. 60/939,353, filed May 21, 2007, entitled “METHODS AND APPARATUS FOR FINDING A SUBSTRATE NOTCH CENTER” (Attorney Docket No. 11244/L);
U.S. Patent Application Ser. No. 60/939,343, filed May 21, 2007, entitled “METHODS AND APPARATUS TO CONTROL SUBSTRATE BEVEL AND EDGE POLISHING PROFILES OF EPITAXIAL FILMS” (Attorney Docket No. 11417/L);
U.S. Patent Application Ser. No. 60/939,219, filed May 21, 2007, entitled “METHODS AND APPARATUS FOR POLISHING A NOTCH OF A SUBSTRATE USING A SHAPED BACKING PAD” (Attorney Docket No. 11483/L);
U.S. Patent Application Ser. No. 60/939,342, filed May 21, 2007, entitled “METHODS AND APPARATUS FOR REMOVAL OF FILMS AND FLAKES FROM THE EDGE OF BOTH SIDES OF A SUBSTRATE USING BACKING PADS” (Attorney Docket No. 11564/L);
U.S. Patent Application Ser. No. 60/939,350, filed May 21, 2007, entitled “METHODS AND APPARATUS FOR USING A BEVEL POLISHING HEAD WITH AN EFFICIENT TAPE ROUTING ARRANGEMENT” (Attorney Docket No. 11565/L);
U.S. Patent Application Ser. No. 60/939,344, filed May 21, 2007, entitled “METHODS AND APPARATUS FOR USING A ROLLING BACKING PAD FOR SUBSTRATE POLISHING” (Attorney Docket No. 11566/L);
U.S. Patent Application Ser. No. 60/939,333, filed May 21, 2007, entitled “METHODS AND APPARATUS FOR SUBSTRATE EDGE POLISHING USING A POLISHING ARM” (Attorney Docket No. 11567/L);
U.S. Patent Application Ser. No. 60/939,337, filed May 21, 2007, entitled “METHODS AND APPARATUS FOR HIGH PERFORMANCE SUBSTRATE BEVEL AND EDGE POLISHING IN SEMICONDUCTOR MANUFACTURE” (Attorney Docket No. 11809/L);
U.S. Patent Application Ser. No. 60/939,212, filed May 21, 2007, entitled “METHODS AND APPARATUS FOR IDENTIFYING A SUBSTRATE EDGE PROFILE AND ADJUSTING THE PROCESSING OF THE SUBSTRATE ACCORDING TO THE IDENTIFIED EDGE PROFILE” (Attorney Docket No. 11695/L);
U.S. Patent Application Ser. No. 60/99,228, filed May 21, 2007, entitled “METHODS AND APPARATUS FOR POLISHING A NOTCH OF A SUBSTRATE BY SUBSTRATE VIBRATION” (Attorney Docket No. 11952/L); and
U.S. Patent Application Ser. No. 60/939,209, filed May 21, 2007, entitled “METHODS AND APPARATUS FOR CONTROLLING THE SIZE OF AN EDGE EXCLUSION ZONE OF A SUBSTRATE” (Attorney Docket No. 11987/L).
FIELD OF THE INVENTIONThe present invention relates generally to electronic device processing, and more particularly to methods and apparatus for cleaning an edge of a substrate.
BACKGROUND OF THE INVENTIONDuring electronic device manufacturing, undesirable materials may build up on the edge of a substrate. The materials may include dielectrics, photoresist and metals used in IC manufacture. Therefore, it may be desirable to clean or polish the bevel and edge of the substrate to remove these materials. What is needed are systems, methods and apparatus for cleaning the edge of substrates without damaging the major surfaces of the substrates.
SUMMARY OF THE INVENTIONIn aspects of the invention, an apparatus is provided for concurrently chemically and mechanically polishing a substrate edge. The apparatus comprises a substrate support adapted to rotate a substrate; a polishing head adapted to contact an edge of the substrate, the polishing head including a first channel adapted to apply a first fluid to the edge of the substrate; a second channel adapted to direct a second fluid onto a major surface of the rotating substrate; and a third channel adapted to direct a third fluid at the major surface of the substrate and to prevent the second fluid from diluting the first fluid.
In other aspects of the invention, a system is provided for concurrently chemically and mechanically polishing a substrate edge. The system comprises a substrate support adapted to rotate a substrate; a polishing head, adapted to contact an edge of a substrate, the polishing head including a first channel adapted to apply a first fluid to the edge of the substrate; a second channel adapted to direct a second fluid onto a major surface of the rotating substrate; a third channel adapted to direct a third fluid at the major surface of the substrate and to prevent the second fluid from diluting the first fluid; and a controller adapted to operate the concurrent chemical and mechanical polishing of the edge of the substrate.
In yet other aspects of the invention a method is provided for concurrently chemically and mechanically polishing a substrate edge. The method includes the steps of (1) rotating a substrate; (2) contacting an edge of the substrate with a polishing head; (3) applying a first fluid to the edge of the substrate via the polishing head; (4) directing a second fluid onto a major surface of the rotating substrate; and (5) directing a third fluid at the major surface of the substrate, wherein the third fluid prevents the second fluid from diluting the first fluid.
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. The edge of a substrate may be polished by application of an abrasive polishing pad or film contacting the substrate edge via a polishing head and by application of chemicals onto the substrate edge, as the substrate is rotated or otherwise moved (e.g., oscillated). As the substrate rotates, deionized water (hereinafter “DI water”) may be applied to the major surface (non-beveled and non-edge surface) of the substrate to prevent potential contamination and to remove material that accumulates as a result of polishing/cleaning. However, it may be undesirable for the DI water to contact the polishing head or dilute the chemicals. According to the present invention, a curtain of fluid, and in a preferred embodiment a gas, such as N2, is directed at the major surface of the substrate such that the gas prevents the DI water from contacting the polishing head and/or diluting the polishing chemicals. In some embodiments the curtain of gas may be curbed to form an arc surrounding the area on the substrate to be polished, such that the interior of the arc faces the polishing head. In some embodiments, the interior of the arc may face the DI water supply to contain the DI water and push it away from the polishing head.
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The pad 204 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 suitable materials may be used. Such materials may have resilience or an ability to conform that is a function of the thickness or density of the pad 204. 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 degree to which the pad 204 may conform to the substrate edge 104 may be adjustable. For example, the pad 204 may be, or include, an inflatable bladder, as described in Application Ser. No. 60/939,333 (Attorney Docket No. 11567/L), cited above, which may be inflatable by air, liquid or other fluid. The amount of fluid filling the pad 204 may be adjusted, such that the pad 204 may suitably conform to the substrate edge 104.
The substrate 100 may be rotated, for example, in a horizontal plane. The substrate edge 104 may be aligned with, or normal to, the polishing tape 206, pad 204 and/or polishing head 201. 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.
In the embodiment described herein, as the substrate 100 rotates, the polishing head 201 may rock around the substrate edge 104 to polish the entire edge 104. The angle of rocking may include, for example, plus or minus 90 degrees. Other rocking angles may be used. In operation, this is achieved by angularly translating the head 201, and consequently the backing pad 204 and polishing tape 206 in contact with, and contoured to, the substrate edge 104, around an axis that is tangential to the outer edge 110 of the substrate 100 as it is rotated. In some embodiments, the head 201 may be adapted to continuously or intermittently oscillate between the various positions. The head 201 may be moved by drivers (not shown) under the direction of a programmed or user operated controller 210 (shown in
In some embodiments, fluids or chemicals may be used to aid in the polishing or washing away of accumulated particles, and may be delivered to the substrate edge 104, as further described below with respect to
As described above, in some embodiments, the controller 210 (shown in
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While in the exemplary embodiment shown here, the nozzle 408 is positioned at a 90 degree angle with respect to the major surface 102 of the substrate 100, in alternate embodiments the nozzle may be positioned at a different angle with respect to the major surface 102 of the substrate 100. For example, when the nozzle 408 is perpendicular (or 90 degrees) to the major surface 102 of the substrate 100, the N2 curtain may also flow in a perpendicular direction to the major surface 102 of the substrate 100. When the N2 curtain contacts with the major surface of the substrate 100, it may flow towards both the polishing head 402 and the DI water, thereby essentially pushing both the chemicals from the DI water to keep them separate. In another exemplary embodiment, the nozzle 408 may be angled towards the DI water, such that the N2 curtain pushes the DI water away from the polishing head 402, further preventing chemical dilution, but may have no effect on the chemicals contacting the substrate edge 104. In yet another exemplary embodiment, the nozzle 408 may be angled towards the polishing head 402, such that the DI water may be allowed to flow towards the polishing head 402, to a certain extent, but the chemicals are prevented from contacting the major surface 102 of the substrate 100.
In some embodiments the chemicals may be applied to and/or through the tape 206 and/or the pad 406 or roller. The backing plate 404 may include one or more channels 502 adapted to drip or spray the fluid directly onto or into the pads 204, 406. Alternatively, the pad 406 may be inflatable and may include a bladder (not shown) with a semi-permeable membrane that allows fluid to be slowly released and transmitted to the polishing tape 206 (e.g., through the pad). In such embodiments, the pad 204, 406 may be covered by, made of, and/or include, material that absorbs and/or retains the fluids used (e.g., polyvinyl alcohol (PVA), etc.). In other embodiments, the chemicals may be sprayed directly onto the substrate 100.
In an alternative embodiment, instead of a polishing pad 406 and/or in combination with the polishing pad 406, heating elements (not shown) may be used to provide temperature assistance to enhance the wet etch rate of the chemicals used to polish/clean the substrate edge 104. The applied heat may be controlled at different locations to control the resulting material removal profile. As with the backing plate, the materials that enclose the heating elements may be flexible/pliable materials such as rubber, polyimide, etc.
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Additionally, the present invention may employ gravity or suction to cause the runoff not to contaminate or contact other parts of the substrate 100 or system 200. Further, the substrate edge 104 may be cleaned/polished by energy (e.g., megasonic energy), which may be applied to the substrate edge 104 via fluid carrying such energy.
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It should be understood that the inventive edge polishing apparatus described herein may be employed in apparatuses other than those adapted for bevel and edge polishing and/or removal of films on substrates. Further, as will be apparent to those of ordinary skill in the art, the apparatus describe herein may be employed to polish and/or remove films on an edge of a substrate supported in any orientation (e.g., horizontal, vertical, diagonal, etc).
Further, it should be understood that 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.
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. 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 for concurrently chemically and mechanically polishing a substrate edge, the apparatus comprising:
- a substrate support adapted to rotate a substrate;
- a polishing head adapted to contact an edge of the substrate, the polishing head including a first channel adapted to apply a first fluid to the edge of the substrate;
- a second channel adapted to direct a second fluid onto a major surface of the rotating substrate; and
- a third channel adapted to direct a third fluid at the major surface of the substrate and to prevent the second fluid from diluting the first fluid.
2. The apparatus of claim 1 wherein the first channel is further adapted to apply the first fluid to the edge of the substrate where the polishing head contacts the edge.
3. The apparatus of claim 1 wherein the polishing head includes one or more sponges adapted to contact the edge of the substrate.
4. The apparatus of claim 3 wherein the first channel provides the first fluid to the one or more sponges.
5. The apparatus of claim 1 wherein the polishing head includes a pad.
6. The apparatus of claim 1 wherein the polishing head includes a polishing tape.
7. The apparatus of claim 1 wherein the polishing head includes a conformal backing plate.
8. The apparatus of claim 1 wherein the polishing head includes a shaped backing plate.
9. The apparatus of claim 1 wherein the second fluid is deionized water.
10. The apparatus of claim 1 wherein the shape of the third fluid forms an arc surrounding the edge of the substrate contacted by the polishing head and a portion of the major surface of the substrate.
11. A system for concurrently chemically and mechanically polishing a substrate edge, the system comprising:
- a substrate support adapted to rotate a substrate;
- a polishing head adapted to contact an edge of a substrate,
- the polishing head including a first channel adapted to apply a first fluid to the edge of the substrate;
- a second channel adapted to direct a second fluid onto a major surface of the rotating substrate;
- a third channel adapted to direct a third fluid at the major surface of the substrate and to prevent the second fluid from diluting the first fluid; and
- a controller adapted to operate the concurrent chemical and mechanical polishing of the edge of the substrate.
12. The system of claim 11 wherein the shape of the third fluid forms an arc surrounding the edge of the substrate contacted by the polishing head and a portion of the major surface of the substrate.
13. The system of claim 12, further comprising a thin curved slit nozzle adapted to form the arc shape of the third fluid.
14. The system of claim 11 wherein the third fluid is N2.
15. The system of claim 11 wherein the controller is adapted to operate the direction of at least one of the second and third fluids.
16. The system of claim 11 wherein the controller is adapted to operate the application of the first fluid to the edge of the substrate.
17. The system of claim 11 wherein the first channel is further adapted to apply the first fluid to the edge of the substrate where the polishing head contacts the edge.
18. The system of claim 11 wherein the polishing head includes one or more sponges adapted to contact the edge of the substrate.
19. The system of claim 18 wherein the first channel provides the first fluid to the one or more sponges.
20. A method for concurrently chemically and mechanically polishing a substrate edge, the method comprising:
- rotating a substrate;
- contacting an edge of the substrate with a polishing head;
- applying a first fluid to the edge of the substrate via the polishing head;
- directing a second fluid onto a major surface of the rotating substrate; and
- directing a third fluid at the major surface of the substrate, wherein the third fluid prevents the second fluid from diluting the first fluid.
21. The method of claim 20 further comprising:
- arcing the third fluid such that the arc surrounds the edge of the substrate contacted by the polishing head and a portion of the major surface of the substrate.
22. The method of claim 20 further comprising:
- rocking the polishing head about the edge of the substrate.
23. The method of claim 20 further comprising:
- pressing a polishing tape against the edge of the substrate via the polishing head.
24. The method of claim 20 further comprising:
- pressing a polishing pad against the edge of the substrate via the polishing head.
25. The method of claim 20 wherein the polishing head includes at least one sponge, and the first fluid is applied to the edge of the substrate via the at least one sponge.
Type: Application
Filed: Feb 28, 2008
Publication Date: Aug 28, 2008
Applicant:
Inventors: Sen-Hou Ko (Sunnyvale, CA), Zhenhua Zhang (San Jose, CA), Yufei Chen (San Jose, CA), Wei-Yung Hsu (Santa Clara, CA)
Application Number: 12/039,418
International Classification: B24B 9/02 (20060101); B24B 57/02 (20060101);