| 摘要 |
PROBLEM TO BE SOLVED: To provide an abrasive and a polishing method by which a surface to be polished of a substrate can be polished at high speed and stability in long-time use is also improved even in the case where the concentration of silicon-oxide particles is low, the abrasive containing silicon-oxide particles used for polishing a sapphire substrate as abrasive grains.SOLUTION: An abrasive for chemical and mechanical polishing is adapted for polishing a surface to be polished of a sapphire substrate and contains first silicon-oxide particles of which the average primary particle size is 5 to 20 nm, second silicon-oxide particles of which the average primary particle size is 40 to 110 nm, alkali metal salt and water. The ratio of the first silicon-oxide particles in the total quantity of the first silicon-oxide particles and the second silicon-oxide particles is 0.7 to 40 mass%. A polishing method is also disclosed for polishing the surface to be polished of the sapphire substrate via the relative motions of both the surface to be polished of the sapphire substrate and the polishing pad by supplying the abrasive to a polishing pad and bringing both the surface to be polished of the sapphire substrate and the polishing pad into contact. |
