| abstract |
A polishing composition for use in polishing a substrate for a magnetic disk comprises silicon dioxide; a first compound containing at least one compound selected from the group consisting of orthophosphoric acid, diphosphoric acid, polyphosphoric acid, metaphosphoric acid, methyl acid phosphate, ethyl acid phosphate, ethyl glycol acid phosphate, phytic acid, 1-hydroxyethylidene-1,1-diphosphonic acid, sodium metaphosphate and acidic sodium hexametaphosphate; a second compound containing at least on salt produced by a neutralisation reaction of each of orthophosphoric acid, diphosphoric acid, polyphosphoric acid, metaphosphoric acid, methyl acid phosphate, ethyl acid phosphate, ethyl glycol acid phosphate, phytic acid, 1-hydroxyethylidene-1,1-diphosphonic acid with ammonia hydrogen peroxide; and water. The polishing composition may further contain a polishing accelerator e.g. citric acid, succinic acid. Also shown is a method for polishing a substrate using the above composition. |