| 摘要 |
PROBLEM TO BE SOLVED: To form a white and dense bismuth film during the substitution plating of bismuth on a copper based stock material. SOLUTION: In the substitution plating bath of bismuth, soluble bismuth salt and base acid are contained, while a specified thio-amino carboxylic acid or its salt (methionine or the like), an aliphatic mercaptocarboxylic acid or its salt (such as mercaptosuccinic acid), sulfides (thiodiglycol, 4, 7-dithiadecane-1, 10-diol or the like), and thiouria derivative (1, 3-bis(3-pyridylmethyl)-2-thiourea or the like) is selected for a copper dissolving agent. Since the specified sulfur-containing compound is used for the copper dissolving agent, the electrode potential difference between the complexed copper ion and bismuth ion can be adequately adjusted, and a white and dense bismuth film can be obtained thereby. COPYRIGHT: (C)2006,JPO&NCIPI
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