NPGS: Free Standing AuPd Film

This structure required three patterning steps. Gold registration marks and bonding pads were put down in the first step. Then, after aligning to the registration marks, the center 1 um wide strip was patterned and processed using evaporated AuPd. Because the AuPd cracked where it crossed onto the leads to the bonding pads, a third step was used to put thick gold patches on the cracks. (The patches can be seen on the leads at the top of the picture.) The sample was then mounted and connections made using a gold ball bonder. Finally, the silicon substrate was etched using a reactive ion etching system. About 1 um of undercutting can be seen around the leads, which was enough to leave the narrow AuPd strip free-standing.

This work was done in Dr. Martin Wybourne's research lab when he was at the University of Oregon.