Eliminating the galvanic effect for microdevices fabricated with PolyMUMPs®

The galvanic effect may notably damage associated micro-electro-mechanical devices fabricated with processes involving electrochemical steps. This effect is commonly observed when a significant amount of gold is used to design MEMS devices that are fabricated using PolyMUMPsreg. To study and overcome the galvanic effect on these devices, three methods are proposed: (1) connecting the device to a poly0 ring; (2) increasing the device surface area and (3) grounding the device to the substrate. The three methods are compared for their effectiveness in preventing galvanic corrosion. It is observed that although all three methods can considerably restrain the galvanic effect, grounding the device to the substrate is the best solution.