Non-planar surface structures and process for microelectromechanical systems
First Claim
1. A method of making a microelectromechanical system (MEMS) device, comprising:
- providing a substrate;
forming a sacrificial layer over the substrate;
partially removing a portion of the sacrificial layer so as to form at least one void that extends through less than the entire thickness of the sacrificial layer, wherein the at least one void has a depth dimension in a range of about 100 angstroms to about 500 angstroms as measured perpendicular to the substrate;
forming an electrically conductive layer over at least a portion of the sacrificial layer and the at least one formed void, thereby forming a non-planar interface between the electrically conductive layer and the sacrificial layer, and removing the sacrificial layer to form a cavity between the substrate and the electrically conductive layer.
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Accused Products
Abstract
Methods of making MEMS devices including interferometric modulators involve depositing various layers, including stationary layers, movable layers and sacrificial layers, on a substrate. Voids are formed in one or more of the various layers so as to form a non-planar surface on the movable and/or the stationary layers. The voids are formed to extend through less than the entire thickness of the layer where they are being formed. Other layers may be formed over the formed voids. Removal of the sacrificial layer from between the resulting non-planar movable and/or stationary layers results in a released MEMS device having reduced contact area between the movable and stationary layers when the MEMS device is actuated. The reduced contact area results in lower adhesion forces and reduced stiction during actuation of the MEMS device. These methods may be used to manufacture released and unreleased interferometric modulators.
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Citations
30 Claims
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1. A method of making a microelectromechanical system (MEMS) device, comprising:
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providing a substrate;
forming a sacrificial layer over the substrate;
partially removing a portion of the sacrificial layer so as to form at least one void that extends through less than the entire thickness of the sacrificial layer, wherein the at least one void has a depth dimension in a range of about 100 angstroms to about 500 angstroms as measured perpendicular to the substrate;
forming an electrically conductive layer over at least a portion of the sacrificial layer and the at least one formed void, thereby forming a non-planar interface between the electrically conductive layer and the sacrificial layer, and removing the sacrificial layer to form a cavity between the substrate and the electrically conductive layer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method of making an interferometric modulator, comprising:
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providing a substrate;
forming a first electrically conductive layer over at least a portion of the substrate;
forming a first dielectric layer over at least a portion of the first electrically conductive layer;
partially removing a portion of a lower layer, wherein the lower layer comprises one of the first dielectric layer, a layer between the first dielectric layer and the substrate, and the substrate so as to form at least one void that extends through less than the entire thickness of the lower layer in which the void is formed;
forming a sacrificial layer over at least a portion of the first dielectric layer and the at least one formed void;
forming a second electrically conductive layer over the sacrificial layer, and selectively removing the sacrificial material against the first dielectric layer. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19)
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20. An interferometric modulator, comprising:
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a substrate;
a first electrically conductive layer over at least a portion of the substrate;
a first dielectric layer over at least a portion of the first electrically conductive layer, the first dielectric layer comprising at least one raised portion in the first dielectric layer, the at least one raised portion having a cross sectional dimension in a range of about 2 micrometers to about 5 micrometers as measured parallel to the substrate and a height dimension of about 100 angstroms to about 500 angstroms as measured perpendicular to the substrate;
a second electrically conductive layer separated from the first dielectric layer by a cavity; and
a support structure arranged over at least a portion of the substrate and configured to support the second electrically conductive layer. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28)
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29. A method of making a microelectromechanical system (MEMS) device, comprising:
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providing a substrate;
forming a sacrificial layer over the substrate;
patterning the sacrificial layer;
partially removing a portion of the patterned sacrificial layer by etching so as to form at least one void that extends through less than the entire thickness of the sacrificial layer;
forming an electrically conductive layer over at least a portion of the sacrificial layer and the at least one formed void, thereby forming a non-planar interface between the electrically conductive layer and the sacrificial layer; and
removing the sacrificial layer to form a cavity between the substrate and the electrically conductive layer. - View Dependent Claims (30)
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Specification