Conductive etch stop for etching a sacrificial layer

In one embodiment a micro device is formed by depositing a sacrificial layer over a metallic electrode, forming a moveable structure over the sacrificial layer, and then etching the sacrificial layer with a noble gas fluoride. Because the metallic electrode is comprised of a metallic material that also serves as an etch stop in the sacrificial layer etch, charge does not appreciably build up in the metallic electrode. This helps stabilize the driving characteristic of the moveable structure. In one embodiment, the moveable structure is a ribbon in a light modulator.