System and method for a differential comb drive MEMS

A method of fabricating a microelectromechanical systems (MEMS) device, the method comprising:

• forming a first material layer at a first surface of a substrate;
• forming a conductive layer over the first material layer;
• patterning the conductive layer to form
• a membrane connected to a first overlapping portion,
• a first extension region, the first extension region connected to a second overlapping portion that overlaps the first overlapping portion in a plane of the first surface, and
• a second extension region, the second extension region connected to a third overlapping portion that overlaps the first overlapping portion in the plane of the first surface;
• forming a second material layer over the conductive layer;
• and
• releasing the membrane, the first extension region, and the second extension region in a release etch, wherein
• the releasing causes the first extension region to deflect in a first direction during the release etch, and
• the releasing causes the second extension region to deflect in a second direction during the release etch, the second direction different from the first direction.

A method of fabricating a microelectromechanical systems (MEMS) device, the method comprising:

• forming a plurality of trenches in a substrate;
• forming a membrane overlapping a first subset of the plurality of trenches;
• forming a first extension region overlapping a second subset of the plurality of trenches, the first extension region;
• forming a second extension region overlapping a third subset of the plurality of trenches, the second extension region;
• and
• releasing the membrane, the first extension region, and the second extension region in a release etch, wherein
• the releasing causes the first extension region to deflect in a first direction during the release etch, and
• the releasing causes the second extension region to deflect in a second direction during the release etch, the second direction different from the first direction.