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US 5,847,454 AGranted
Electrically isolated released microstructures
AssigneeCornell Research Foundcatton, Inc.
InventorsKevin A. Shaw, Z. Lisa Zhang, Noel C. MacDonald
Life of this patent
Estimating the term…
Abstract
A single mask, low temperature reactive ion etching process for fabricating high aspect ratio, released single crystal microelectromechanical structures independently of crystal orientation.
Claims38
A microelectromechanical structure fabricated in a single crystal substrate independently of crystal orientation by a low temperature, single mask process, comprising:
- a single crystal wafer forming a substrate having a top surface;
- trench means in the top surface of said substrate defining a contact means, a released beam and interconnect means extending between said beam and said contact means on the surface of said substrate, said contact means, beam and interconnect means being spaced from and surrounded by said substrate, said beam being supported by said interconnect means and being movable with respect to said substrate;
- and
- an electrically conductive coating on said contact means, released beam and interconnect means and on said substrate, said trench means including undercut walls electrically isolating the coating on said contact means, beam and interconnect means from the coating on said substrate.
1 more element
A microelectromechanical structure, comprising:
- a substrate having a top surface;
- a trench formed in said substrate and including side walls and a floor;
- a released microelectromechanical beam spaced above said floor and a fixed mesa on said floor and supporting said beam for motion with respect to said substrate, said beam and said mesa being located within and completely surrounded by said trench side walls and being fabricated from said substrate, said mesa including a contact pad and interconnect means between said beam and said contact pad to support said beam;
- a dielectric layer on said released beam and mesa and on said top surface of said substrate surrounding said trench;
- an electrically conductive layer on said dielectric layer providing an electrical connection between said beam and said contact pad by way of said interconnect means;
- and
- means electrically isolating the conductive layer on said substrate from the conductive layer on said released beam and mesa.
4 more elements
A microelectromechanical structure, comprising:
- an integrated circuit wafer incorporating an electrical connector for the integrated circuit and incorporating a trench having a floor and substantially vertical walls defining a fixed mesa and relatively movable beam structure supported by said mesa within said trench, said mesa and said beam being of the same material as, and being fabricated from, said wafer;
- and
- a conductive layer on, and electrically insulated from, said wafer, said mesa and said beam, said trench providing electrical isolation between the conductive layer on said substrate and the conductive layer on said mesa and beam structure;
- said connector being electrically isolated from, and connectable to, said mesa and beam conductive layer.
1 more element
A microelectromechanical structure, comprising:
- a single crystal integrated circuit wafer incorporating an electrical connector for an integrated circuit;
- a trench in said wafer incorporating a floor and a substantially vertical side wall, said trench being shaped to define a beam portion extending from the side wall;
- an undercut cavity extending along the side wall and extending beneath said beam portion to release at least a part of the beam portion for relative motion with respect to the substrate;
- and
- a conductive layer on said wafer and on said released beam portion in electrical contact with said connector.
2 more elements
A microelectromechanical structure, comprising:
- a substrate having a top surface;
- a trench formed in said substrate and including side walls and a floor;
- released microelectromechanical beam means and a fixed mesa supporting said beam means located within and completely surrounded by said trench and being fabricated from said substrate, said beam means comprising a grid of mechanically interconnected beams for providing increased mass to said beam means;
- a dielectric layer on said released beam means and said mesa and on said top surface of said substrate surrounding said trench;
- an electrically conductive layer on said dielectric layer;
- and
- means electrically isolating the conductive layer on said substrate from the conductive layer on said beam means and mesa.
4 more elements
A microelectromechanical structure, comprising:
- a substrate having a top surface;
- a trench formed in said substrate and including side walls and a floor;
- released microelectromechanical beam means and a fixed mesa supporting said beam means located within and completely surrounded by said trench and being fabricated from said substrate, said beam means having a predetermined spring constant;
- means adjusting said spring constant;
- a dielectric layer on said released beam means and said mesa and on said top surface of said substrate surrounding said trench;
- an electrically conductive layer on said dielectric layer;
- and
- means electrically isolating the conductive layer on said substrate from the conductive layer on said beam means and mesa.
5 more elements
A microelectromechanical structure, comprising:
- a substrate having a top surface;
- a trench formed in said substrate and including side walls and a floor;
- released microelectromechanical beam means and a fixed mesa supporting said beam means located within and completely surrounded by said trench and being fabricated from said substrate;
- a dielectric layer on said released beam means and said mesa and on said top surface of said substrate surrounding said trench;
- an electrically conductive layer on said dielectric layer;
- a layer of tungsten between said dielectric layer and said conductive layer;
- and
- means electrically isolating the conductive layer on said substrate from the conductive layer on said beam means and mesa.
5 more elements
A microelectromechanical structure, comprising:
- a substrate having a top surface;
- a trench formed in said substrate and including side walls and a floor;
- released microelectromechanical beam means and a fixed mesa supporting said beam means located within and completely surrounded by said trench and being fabricated from said substrate, said beam means being mounted on said mesa for torsional motion with respect to said substrate;
- a dielectric layer on said released beam means and said mesa and on said top surface of said substrate surrounding said trench;
- an electrically conductive layer on said dielectric layer;
- and
- means electrically isolating the conductive layer on said substrate from the conductive layer on said beam means and mesa.
4 more elements
A microelectromechanical structure, comprising:
- a substrate having a top surface;
- a trench formed in said substrate and including side walls and a floor;
- released microelectromechanical beam means and a fixed mesa supporting said beam means located within and completely surrounded by said trench and being fabricated from said substrate, said beam means comprising a spiral microinductor having first and second ends, at least one of said ends being secured to said mesa;
- a dielectric layer on said released beam means and said mesa and on said top surface of said substrate surrounding said trench;
- an electrically conductive layer on said dielectric layer;
- and
- means electrically isolating the conductive layer on said substrate from the conductive layer on said beam means and mesa.
4 more elements
Dependencies are inferred from the claim text.