| 摘要 |
PURPOSE:To reduce the side etching of a barrier metal right under a solder bump by adding a specific amount of ethylene diamine tetraacetic acid to a solution containing a specific amount rate of aqueous ammonia, aqueous hydrogen peroxide and water, and setting the liquid temperature to a specific temperature. CONSTITUTION:An barrier metal 4 except the part right under a solder bump 7 on a wafer 3 is removed by etching with the mixed liquid of aqueous ammonia of 300cc, aqueous hydrogen peroxide of 300cc and water of 500cc and ethylene diamine tetraacetic acid of 25g. Namely, a wafer 3 is immersed in a mixed liquid of 10 deg.C (Preferably 5 to 10 deg.C) by using a wafer holder of single wafer processing to remove the barrier metal 4 except the part right under the solder bump 7 by etching. An average time required for the removal of the barrier metal 4 except the part right under the solder bump 7 by etching is 6 minutes and an amount of side etching is 3 to 5mum. The volume ratio of aqueous hydrogen peroxide and water is 1 to 2 with respect to aqueous ammonia and ethylene diamine tetraacetic acid is not less than 1g with respect to a solution of 100cc. |
