Patent ID: 7299538

Claim:
A method for fabricating an actuator having a recessed, movable electrode, comprising the steps of: (a) forming a stationary electrode having first and second ends on a substrate; (b) depositing a first sacrificial layer on the stationary electrode and the substrate; (c) depositing a second sacrificial layer on the first sacrificial layer; (d) patterning the second sacrificial layer in such a manner that the patterned second sacrificial layer includes a recessed portion on the first sacrificial layer located over the second end of the stationary electrode, and the second sacrificial layer is completely removed from a proximal portion of the first sacrificial layer located over a central portion of the stationary electrode between the first and second ends; (e) forming a movable electrode having a first portion over the patterned recessed portion of the second sacrificial layer and a second portion over the proximal portion of the first sacrificial layer; (f) depositing a structural layer on the first sacrificial layer, the second sacrificial layer, and the movable electrode; and (g) removing a sufficient amount of the first and second sacrificial layers so as to separate the movable electrode from the substrate, wherein the structural layer is supported by the substrate at a fixed end and is freely suspended above the substrate at an opposing suspended end, and wherein the second portion of the movable electrode is separated from the substrate by a distance less than the distance separating the first portion from the substrate.