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 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.
A method of forming a MEMS device, the method comprising:
- etching a first cavity and a second cavity in a topmost dielectric layer of a first substrate, a portion of the topmost dielectric layer being disposed between the first cavity and the second cavity;
- forming a first protrusion on a floor of the first cavity, and a second protrusion on a floor of the second cavity, wherein each of the first protrusion and the second protrusion have a low surface energy relative to the surface energy of a material of the topmost dielectric layer;
- bonding a second substrate to the first substrate;
- and
- after bonding the second substrate to the first substrate, patterning the second substrate to form a first movable element at least partially suspended above the first cavity, wherein the first protrusion is in a path of movement of the first movable element when the first movable element is deflected in a first direction.
A method of forming a MEMS device, the method comprising:
- forming a cavity in a substrate;
- forming a protrusion that extends from a floor of the cavity, the protrusion comprising:
- a dielectric layer;
- and
- a conductive film over sidewalls and a top surface of the dielectric layer, wherein a first material of the conductive film has a low surface energy relative to the surface energy of a second material of the dielectric layer;
- and
- positioning a movable element above the cavity such that the movable element is configured to contact the protrusion when the movable element is deflected vertically downwards into the cavity.
Dependencies are inferred from the claim text.