| 摘要 |
PROBLEM TO BE SOLVED: To provide an etching solution and an etching method, in etching using an etching solution containing cerium (TV) nitrate ammonium capable of surely preventing the precipitation of insoluble compounds, further good in the etching rate and excellent in mass-productivity. SOLUTION: In this etching solution, the concentration of nitric acid is 8 to 15 wt.%, and the concentration of cerium (TV) nitrate ammonium is >20 to 30 wt.%. The etching method uses the same etching solution. In the etching method, cerium (TV) nitrate ammonium is replenished into the etching solution in the process of etching in such a manner that the weight ratio of quadrivalent cerium to hexavalent chromium is controlled to >=17.
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