摘要 |
<p><P>PROBLEM TO BE SOLVED: To improve the efficiency of a polishing process by keeping an excellent wafer polishing rate while suppressing the metallic contamination of the wafer taking into consideration the balance of the metallic contamination of the wafer and the polishing rate of the wafer. Ž<P>SOLUTION: A slurry is supplied to a column 12 filled with chelating fiber. Successively, pure water is supplied to the column 12, and then a nitric acid solution is supplied to the column 12. In this case, the metal captured by the chelating fiber dissolves in the nitric acid solution. The nitric acid solution containing the dissolved metal is supplied to an analyzer 15 to measure the amount of the metal dissolved in the solution. The measured results of the analyzer 15 is sent to an added amount analyzing apparatus 16 to decide the optimum additional amount of the chelating agent at the measuring time. The chelating agent is supplied to a slurry supplying reservoir 5 according to the decided amount. Ž<P>COPYRIGHT: (C)2005,JPO&NCIPI Ž</p> |