| 摘要 |
PROBLEM TO BE SOLVED: To remove polluted metal other than a metallic surface exposed by patterning in a cleaning step for a substrate, without etching the metallic material. SOLUTION: A cleaning solution includes one of aqueous carboxylic acid like oxalic acid, carboxylic ammonium salt and carboxylic acid with an amino- group. A silicon substrate 1 with a gate wiring 6 is cleaned. The polluted metal on the silicon substrate 1 is removed by the carboxylic solution in a chelate effect with the metal. In this way, without etching TiN or W as a low-resistance gate material, the polluted metal can be removed. An adverse effect of the polluted metal on characteristics is prevented, while the reliability of device is ensured.
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