MEMS Structure and Method of Forming Same
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsYi Heng Tsai, Chia-Hua Chu, Kuei-Sung Chang
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Abstract
A microelectromechanical system (MEMS) device includes a substrate and a movable element at least partially suspended above the substrate and having at least one degree of freedom. The MEMS device further includes a protrusion extending from the substrate and configured to contact the movable element when the movable element moves in the at least one degree of freedom, wherein the protrusion comprises a surface having a water contact angle of higher than about 15° measured in air.
Claims20
A MEMS device, comprising:
- a first substrate;
- a plurality of dielectric layers over the first substrate, wherein a topmost layer of the plurality of dielectric layers has a cavity formed therein;
- a second substrate, the second substrate comprising a movable element at least partially suspended above the cavity, the movable element having at least one degree of freedom, the second substrate bonded to the topmost layer of the plurality of dielectric layers;
- and
- a protrusion extending upwards from a floor of the cavity, the protrusion being in a motion path of the at least one degree of freedom of the movable element, the protrusion comprising:
- a dielectric material;
- and
- an electrically conductive film over an upper surface and sidewalls of the dielectric material, wherein the electrically conductive film has a lower surface energy than a surface energy of the dielectric material.
A MEMS device, comprising:
- a substrate comprising a plurality of interconnect layers embedded in a plurality of stacked dielectric layers;
- a series of interdigitated fingers, wherein each of the series of interdigitated fingers is fixed at one end and is free at another end, free ends of the series of interdigitated fingers extend over a cavity formed in the substrate;
- and
- a protrusion extending upwards from a floor of the cavity, the protrusion comprising a conductive film electrically connected to a first interconnect layer of the plurality of interconnect layers, wherein a first interdigitated finger of the series of interdigitated fingers contacts the protrusion when the series of interdigitated fingers are deflected downwards towards the floor of the cavity.
A method of forming a MEMS device, the method comprising:
- forming a cavity in a first substrate;
- patterning a second substrate to form a series of interdigitated fingers, wherein each of the series of interdigitated fingers is fixed at one end and is free at another end;
- mounting the second substrate atop the first substrate, wherein free ends of the series of interdigitated fingers extend over the cavity;
- forming a plurality of protrusions extending from a floor of the cavity, wherein a first interdigitated finger of the series of interdigitated fingers will contact a first protrusion of the plurality of protrusions when the series of interdigitated fingers are deflected downwards towards the floor of the cavity;
- electrically coupling the first protrusion of the plurality of protrusions to the series of interdigitated fingers;
- and
- electrically coupling a second protrusion of the plurality of protrusions to a potential voltage node that provides a voltage of an opposite polarity to that of a voltage on the series of interdigitated fingers.
Dependencies are inferred from the claim text.