Mems devices and methods of forming same
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorBruce C.S. Chou
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Abstract
The present invention provides a MEMS structure comprising confined sacrificial oxide layer and a bonded Si layer. Polysilicon stack is used to fill aligned oxide openings and MEMS vias on the sacrificial layer and the bonded Si layer respectively. To increase the design flexibility, some conductive polysilicon layer can be further deployed underneath the bonded Si layer to form the functional sensing electrodes or wiring interconnects. The MEMS structure can be further bonded to a metallic layer on top of the Si layer and the polysilicon stack.
Claims20
A micro-electromechanical system (MEMS), comprising:
- a substrate;
- an isolation layer on top of the substrate, wherein the isolation layer comprises silicon nitride;
- a sacrificial layer on top of the isolation layer, wherein the sacrificial layer has a flat surface and at least one opening extending therethrough;
- a wafer layer bonded to the sacrificial layer, wherein the wafer layer has at least one MEMS via;
- a conductor stack within the at least one MEMS via;
- a MEMS structure formed in the wafer;
- and
- a cavity between the isolation layer and the MEMS structure.
(canceled)
A system, comprising:
- a substrate;
- an isolation layer atop the substrate;
- a sacrificial layer atop the isolation layer;
- a first opening extending through the sacrificial layer;
- a wafer layer bonded to the sacrificial layer;
- a second opening extending through the wafer layer, and aligned with the first opening;
- a conductor stack filling the first opening and the second opening, wherein the conductor stack comprises doped polysilicon;
- an etch hole extending through the wafer layer;
- and
- a cavity under a region of the wafer layer.
(canceled)
A system comprising:
- a silicon-containing substrate;
- a nitride layer on the substrate;
- a sacrificial oxide layer on the nitride layer, wherein the sacrificial oxide layer has at least one opening extending therethrough;
- a silicon layer bonded to the sacrificial layer, wherein the silicon layer has at least one MEMS via extending therethrough, the at least one MEMS via being aligned with the at least one opening in the sacrificial oxide layer;
- a polysilicon conductor within the at least one MEMS via and the at least one opening in the sacrificial oxide;
- a MEMS structure formed in the silicon layer;
- and
- a cavity between the nitride layer and the MEMS structure.
Dependencies are inferred from the claim text.