A method for fabricating an electrically isolated MEMS device having an
outer stationary MEMS element and an inner movable MEMS element is
provided that does not use a sacrificial layer. Rather, a pair of spacers
are defined on the outer portions of the upper surface of a conductive
wafer, and an insulating material is deposited thereon. The spacers are
attached to a substrate to define an internal void therein. The wafer is
then patterned to form the outer MEMS element as well as a conductive
member for the inner MEMS element, separated from the outer MEMS element
by a gap. A portion of the insulating layer that is disposed in the gap
is then removed, thereby releasing the inner MEMS element from the
stationary MEMS element.