Method for fabricating a microelectromechanical system (MEMS) device using a pre-patterned bridge
First Claim
Patent Images
1. A method of fabricating a MEMS structure, comprising the steps of:
- (a) providing a wafer having at least a first insulating layer and a second layer;
(b) removing a portion of the first layer through to the second layer to form a bridge member from the first layer;
(c) providing a substrate defining an upper surface, wherein a recess is formed in at least one of the substrate and the wafer;
(d) after step (c), attaching the wafer to the upper surface of the substrate to form a composite structure having an internal void formed therein, wherein the bridge member is aligned with the internal void, and (e) etching through the second layer of the wafer around the periphery of the bridge member to break through into the void and release the bridge from the substrate.
1 Assignment
0 Petitions
Accused Products
Abstract
A method for fabricating MEMS structures includes etching a recess in either an upper surface of a substrate that is bonded to a wafer that ultimately forms the MEMS structure, or to the lower surface of the wafer that is bonded to the substrate. Accordingly, once the etching processes of the wafer are completed, the recess facilitates the release of an internal movable structure within the fabricated MEMS structure without the use of a separate sacrificial material. Furthermore, a bridge, which is preferably insulating, is pre-etched before the wafer is attached to the substrate.
67 Citations
41 Claims
-
1. A method of fabricating a MEMS structure, comprising the steps of:
-
(a) providing a wafer having at least a first insulating layer and a second layer;
(b) removing a portion of the first layer through to the second layer to form a bridge member from the first layer;
(c) providing a substrate defining an upper surface, wherein a recess is formed in at least one of the substrate and the wafer;
(d) after step (c), attaching the wafer to the upper surface of the substrate to form a composite structure having an internal void formed therein, wherein the bridge member is aligned with the internal void, and (e) etching through the second layer of the wafer around the periphery of the bridge member to break through into the void and release the bridge from the substrate. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
-
-
22. A method of fabricating a MEMS structure, comprising the steps of:
-
(a) providing a wafer having at least a first layer and a second layer;
(b) removing a portion of the first layer to form a bridge member;
(c) providing a substrate, wherein a recess is formed in at least one of the substrate and the wafer;
(d) after step (c), attaching the wafer to a substrate to form a composite structure having an internal void formed therein, wherein the bridge member is aligned with the internal void; and
(e) etching through the second layer of the wafer around the periphery of the bridge member to
1) break through into the void,
2) release the bridge from the substrate,
3) form a conductive member extending from the bridge, and
4) form a stationary member from the wafer that is separated from the bridge member by a gap that varies in size in response to bridge member movement. - View Dependent Claims (23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37)
-
-
38. A method of fabricating a MEMS structure, comprising the steps of:
-
(a) providing a wafer;
(b) partially etching into a surface of the wafer to form a recess therein disposed between a pair of spacers;
(c) depositing a layer onto the surface of the wafer in the recess to form a bridge;
(d) attaching the spacers to a substrate to define an internal void; and
(e) etching through the wafer into the void around the periphery of the bridge to release the bridge from mechanical communication with the substrate and to produce a stationary conductive MEMS element attached to the substrate, and a movable conductive MEMS element supported by the bridge and separated by the stationary element via a variable size gap. - View Dependent Claims (39, 40, 41)
-
Specification