| 摘要 |
PURPOSE:To prevent a bonding pad from forming a different film by dipping a wafer in a liquid of etching aluminum, and energizing an ultrafine DC to the liquid to etch. CONSTITUTION:Two electrodes 2a, 2b are inserted separately into etchant 105 in an etching bath 104. The electrode 2a is platinum, the electrode 2b is alumi num, the electrode 2a is connected to ultrafine negative DC current, and the electrode 2b is connected to ultrafine positive DC current. Metallic ions (posi tively charged) and impurity ions generated in the etchant are attracted to the platinum electroded and neutralized. |
