摘要 |
When relatively hard Au bump electrodes are mass-produced by electrolytic plating while ensuring usually required properties such as a non-glossy property and shape-flatness, combination of conditions, such as low liquid temperature, high current density, and low concentration of added Tl (thallium) that is an adjuvant, will be selected by itself. However, in such conditions, there is a problem that it is difficult to maintain the Tl concentration in a plating solution and, when the Tl concentration is reduced, defective appearance of the Au bump electrodes is generated by anomalous deposition. Conventionally, there has been no means to directly monitor minute Tl concentration and the Tl concentration has been controlled by analyzing the plating solution periodically. However, this can not prevent generation of a lot of defective products. One invention of the present application relates to detecting the added amount of Tl in the plating solution by monitoring the voltage applied to the plating solution in formation of bump electrodes by an electrolytic Au plating using a non-cyan based plating solution according to the manufacturing method of a semiconductor integrated circuit device.
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