Method for fabricating an isolated microelectromechanical system (MEMS) device using an internal void
First Claim
1. A method of fabricating a circuit device comprising the steps of:
- (a) providing a wafer and a substrate;
(b) depositing a first layer on the wafer;
(c) depositing a spacer material directly onto the first layer without first etching the first layer;
(d) etching through the spacer material to the first layer to form a recess within a middle portion of the spacer material using an etchant that preferentially etches the spacer material without etching the first layer;
(e) attaching the spacer material to the substrate without an intermediary adhesive layer to form a composite structure having a void disposed therein; and
(f) etching into the wafer towards the substrate to remove a portion of the wafer and release a movable element.
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Accused Products
Abstract
A method for fabricating an electrically isolated MEMS device having an outer stationary MEMS element and an inner movable MEMS element is provided that does not use a sacrificial layer. Rather, a pair of spacers are defined on the outer portions of the upper surface of a conductive wafer, and an insulating material is deposited thereon. The spacers are attached to a substrate to define an internal void therein. The wafer is then patterned to form the outer MEMS element as well as a conductive member for the inner MEMS element, separated from the outer MEMS element by a gap. A portion of the insulating layer that is disposed in the gap is then removed, thereby releasing the inner MEMS element from the stationary MEMS element.
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Citations
21 Claims
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1. A method of fabricating a circuit device comprising the steps of:
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(a) providing a wafer and a substrate; (b) depositing a first layer on the wafer; (c) depositing a spacer material directly onto the first layer without first etching the first layer; (d) etching through the spacer material to the first layer to form a recess within a middle portion of the spacer material using an etchant that preferentially etches the spacer material without etching the first layer; (e) attaching the spacer material to the substrate without an intermediary adhesive layer to form a composite structure having a void disposed therein; and (f) etching into the wafer towards the substrate to remove a portion of the wafer and release a movable element. - View Dependent Claims (2, 3, 4, 5, 6, 9, 10, 11, 12, 13, 14, 15)
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7. A metod of fabricating a circuit device comprising the steps of:
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(a) providing a wafer and a substrate; (b) depositing a first layer on the wafer; (c) depositing a spacer material directly onto the first layer; (d) etching through the spacer material to the first layer to form a recess within a middle portion of the spacer material using an etchant that preferentially etches the spacer materlal without etching the first layer; (e) attaching the spacer material to the substrate to form composite structure having a void disposed therein ; and (f) etching into the wafer toward the substrate to remove a portion of the wafer and release a movable element, wherein step (d) further comprises depositing an insulating layer onto the wafer in the recess. - View Dependent Claims (8)
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16. A method of fabricating a circuit device comprising the steps of:
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(a) providing a wafer and a substrate; (b) partially etching a middle portion of the wafer so as to form a recess in the middle portion of the wafter; (c) depositing a first layer on the partially etched wafer, wherein the first layer is formed over the recess; (d) attaching the first layer to the substrate such that a void is disposed between the substrate and the first layer; (e) forming a movable element in the wafer; and (f) etching into the wafer towards the substrate to remove a portion of the wafer and the first layer to release the movable element. - View Dependent Claims (17, 18, 19, 20)
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21. A method of fabricating a circuit device comprising the steps of:
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(a) providing a wafer and a substrate; (b) depositing a first layer on the wafer; (c) depositing a spacer material on the first layer; (d) selectively etching the first layer independently from selectively etching the spacer material without a sacrificial layer disposed between the first layer and the spacer material to form a recess within a middle portion of the spacer material; (e) attaching the spacer material to the substrate to form a composite structure having a void disposed therein; and (f) etching into the wafer towards the substrate to remove a portion of the wafer and release a movable element, wherein step (d) further comprises depositing an insulating layer onto the wafer in the recess.
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Specification