Staggered vertical comb drive fabrication method
AssigneeJDS Uniphase Corporation
InventorsSteven H. Moffat, John M. Miller
Life of this patent
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Abstract
The invention relates to a method of fabrication of staggered vertical comb drive actuators with relaxed lateral alignment tolerances. A device layer of a wafer is first etched from a front side using a self-aligned two-layer mask to define interdigited fingers of both moving and stationary combs. A second etch step is used for vertically thinning one of the two sets of fingers by selectively removing their top portions. The front side of the wafer is then bonded to a carrier wafer. The wafer is then selectively etched from the back side of the device layer so as to remove lower portions of the second set of fingers, thereby forming interdigited moving and stationary combs having vertically offset fingers.
Claims18
A method for fabricating a staggered vertical comb drive, comprising the steps of:
- a) providing a wafer comprising a device layer;
- b) etching the device layer to form therein two comb structures comprising a first set of fingers interdigited with a second set of fingers;
- c) removing a top portion of each finger from the first set of fingers by etching, so as to vertically shorten the first set of fingers;
- and,
- d) removing a lower portion of each finger from the second set of fingers by etching from a back side of the wafer, so as to vertically shorten the second set of fingers resulting in said second set of fingers being vertically offset from the first set of fingers.
Dependencies are inferred from the claim text.