Patent ID: 8057282

Claim:
A method for polishing at least one of a magnetic, optical and semiconductor substrate in the presence of a polishing medium with a polishing pad, the substrate being fixed within a carrier fixture, the carrier fixture having a channel-free surface, the method comprising: a) securing the substrate in the carrier fixture with the channel-free surface adjacent and parallel to a polishing surface of the polishing pad, the polishing pad having multiple grooves, the multiple grooves having a high-rate path, at least fifty percent of the high-rate path being within twenty percent of a groove trajectory Ï†(r) in polar coordinates referenced to a concentric center of the polishing pad and defined in terms of (1) distance R between the concentric center of the polishing pad and the rotational center of the substrate being polished, (2) radius R c of the carrier fixture, and (3) local angle Î¸ c0 of imaginary grooves in the carrier fixture, as follows: Ï• â¡ ( r ) = âˆ« R - R C r â¢ R R C â¢ sin â¢ â¢ Ï• c + ( tan â¢ â¢ Î¸ c â¢ â¢ 0 ) â¢ ( R R C â¢ cos â¢ â¢ Ï• c + 1 ) ( R R C â¢ cos â¢ â¢ Ï• c + 1 ) - ( tan â¢ â¢ Î¸ c â¢ â¢ 0 ) â¢ R R C â¢ sin â¢ â¢ Ï• c â¢ â¢ â…† r â€² r â€² where Ï• c = cos - 1 â¡ ( R 2 + R C 2 - r 2 2 â¢ RR C ) - Ï€ for â¢ â¢ values â¢ â¢ of â¢ â¢ r â¢ â¢ from â¢ â¢ ( R - R C ) â¢ â¢ to â¢ â¢ ( R + R C ) b) applying polishing medium to the polishing pad adjacent the carrier fixture; and c) rotating the polishing pad and carrier fixture to polish the substrate with the polishing pad and the polishing medium wherein the channel-free surface of the carrier fixture presses against the polishing pad to impede flow of the polishing medium into the substrate and the high-rate groove paths traverse the carrier fixture to promote flow of the polishing medium to the substrate.