US Patent 7677706 Electrostatic actuator and fabrication method

In one embodiment a method of making an electrostatic actuator includes: forming a first conductor over a first substrate to form a first structure; forming a flexible second conductor over a second substrate to form a second structure; forming an etch stop over the first conductor as part of the first structure or over the second conductor as part of the second structure; forming a spacer on the etch stop, the spacer selectively etchable with respect to the etch stop; etching the spacer through to the etch stop at a location of a gap between the first conductor and the second conductor; and bonding the first structure and the second structure together such that the first conductor is located opposite the second conductor across the gap.