High Performance Gold Plating for Microdevices

Gold bumps of high quality have been electrodeposited from a sulfitic gold electrolyte. Periodic recording, both of existing process data and resulting layer properties, yielded a synergistic model to maintain the reliability of the plating process. Sources of nodules and pits, or voids were characterized using SEM and acoustomicroscopy. Further factors that influence quality of gold deposits (hardness, roughness, unitormity) could be optimized.