The influence of cathode agitation on the residual stress of electroplated gold has been investigated. Using a custom-built plating cell, a periodic, reciprocating motion was applied to silicon substrates that were electroplated with soft gold. A commercially available gold sulfite solution was used to deposit the 0.6μm thick gold films using a current density of 3.0mA/cm2 and a bath temperature of 50°C. By increasing the speed of cathode agitation from 0 to 5cm/s, the magnitude of the compressive stress decreased from −64 to −9MPa. The results suggest that cathode agitation significantly alters the mass transport within the electrolytic cell and can be used as a method of stress control in gold electroplating. This finding is potentially significant for plating applications in microelectronics and microsystems that require precise stress control. 
Stress in electroplated gold on silicon substrates and its dependence on cathode agitation