Patent ID: 6354915
Filing Date: 2002-03-12
Classification: B24B,B24D

Abstract:
A method of polishing a substrate surface on a substrate comprising;placing a fluid between the substrate and a thin pad, the thin pad having a polishing layer, the polishing layer further comprising a polishing surface; moving the polishing surface and the substrate surface relative to and biased toward one another as the fluid is maintained between the surfaces, the fluid preventing at least 50% of the surfaces, on average, from touching one another; biasing the surfaces together by applying a uniform force of less than 25 pounds per square inch and compressing the polishing surface by less than 5 microns, thereby causing the polishing surface to exhibit a planar configuration which is parallel to a major portion of the substrate surface, said polishing surface comprising a plurality of nanoasperities; said polishing layer having a thickness of less than or equal to one millimeter, the polishing layer being bonded to a support film, the support film having a thickness of less than or equal to 1 millimeter, the thin pad having an average total thickness of less than or equal to three millimeters, said polishing surface consisting essentially of a polishing material having: i. a density greater than 0.5 g/cm3; ii. a tensile modulus of 0.02 to 5 GigaPascals; iii. a ratio of tensile modulus at 30Â° C. to tensile modulus at 60Â° C. of 1.0 to 2.5; iv. a hardness of 15 to 80 Shore D; v. a yield stress of 300-6000 psi; vi. a tensile strength of 1000 to 15,000 psi; and vii. an elongation to break less than or equal to 500%, said polishing material comprising at least one moiety from a group consisting of: 1. a urethane; 2. a carbonate; 3. an amide; 4. an ester; 5. an ether; 6. an acrylate; 7. a methacrylate; 8. an acrylic acid; 9. a methacrylic acid; 10. a sulphone; 11. an acrylamide; 12. a halide; 13. an imide; 14. a carboxyl; 15. a carbonyl; 16. an amino; 17. an aldehydric and 18. a hydroxyl.