| 摘要 |
The present invention provides a micro-hole plating method for depositing a gold layer within a micro opening of a photoresist. The method applies a plating current, which is either only a positive pulse current or a positive/negative pulse current having an appropriate waveform, and also uses a gold plating solution containing gold iodide complex ions and a non-aqueous solvent. This plating solution is less toxic, not easily oxidized, and has a long life, thus offering great performance comparable with the cyanide-type gold plating solution. According to this method, unevenness of bump surface, bump height variation in the wafer, and the bump surface roughness are reduced, and the resulting gold bumps have highly reliable conduction. In addition to this, the method is immune to a short circuit among electrodes, which is caused by a crack in the resist. |
