Patent ID: 7538927

Claim:
A method for forming a MEMS (micro-electro-mechanical system) device, comprising: etching a first surface of a device wafer to form: a plurality of first spring pads; a first support pad on a first side of a rotational axis; and a plurality of first short stationary comb teeth extending from the first support pad toward the rotational axis; etching a second surface of the device wafer to form: a mirror; first and second beam structures, each connected at a respective proximal end to the mirror and extending to a respective distal end spaced from the mirror; a plurality of second spring pads, wherein the second spring pads and the first spring pads at least partially overlap; a plurality of springs coupling the first and the second beam structures to the second spring pads along the rotational axis so the mirror can rotate about the rotational axis; a first stationary pad on the first side of the rotational axis, wherein the first stationary pad and the first support pad at least partially overlap; a plurality of first long stationary comb teeth extending from the first stationary pad toward the rotational axis, wherein the first long stationary comb teeth and the first short stationary comb teeth at least partially overlap; a plurality of first long rotating comb teeth extending from a first edge of the first and the second beam structures toward the first long stationary comb teeth, the first long rotating comb teeth being interdigitated out-of-plane at their tips with the first short stationary comb teeth, the first long rotating comb teeth being interdigitated in-plane substantially along their lengths with the first long stationary comb teeth.