| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce damage to a semiconductor structure, and to improve surface uniformity of the semiconductor structure by removing a specific part of a polishing object by performing first stage polishing by a fumed abrasive, and removing a residual polishing object by performing second stage polishing by a colloidal silica abrasive. SOLUTION: Since the size of an abrasive grain is in direct proportion to a polishing speed, about 90% of a polishing object is removed at a fast polishing speed in the first stage to form a flat surface. Second slurry 22b is supplied to a polishing pad 14 from a supply pipe 20 at polishing time of the second stage. Since an abrasive in the second slurry 22b is formed in a colloidal state, the abrasive grain is small and uniform, and the abrasive grain size is between about 10 to 100 nm. Since the polishing speed is slow, the selecting ratio to a polishing object becomes large, a dielectric film of residual about 10% can be accurately removed, abrasive can be mass-produced since it becomes a fumed state, a cost is reduced, and since the abrasive grain is large, a great part of the polishing object can be removed in a short time.</p> |
