Method of fabricating a dual single-crystal backplate microphone
AssigneeAnalog Devices, Inc.
InventorsKuang L. Yang, Li Chen, Thomas D. Chen
Life of this patent
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Abstract
A dual backplate MEMS microphone system including a flexible diaphragm sandwiched between two single-crystal silicon backplates may be formed by fabricating each backplate in a separate wafer, and then transferring one backplate from its wafer to the other wafer, to form two separate capacitors with the diaphragm.
Claims15
A method of fabricating a dual-backplate microphone, the method comprising:
- providing a first wafer comprising a first conductive single-crystal backplate and a conductive diaphragm;
- providing a second conductive single-crystal backplate;
- and
- bonding the second conductive single-crystal backplate to the first wafer having the conductive single-crystal backplate, such that the diaphragm is sandwiched between, but electrically isolated from, the first conductive single-crystal backplate and the second conductive single-crystal backplate,
- wherein the conductive diaphragm forms a first variable capacitor with the first conductive single-crystal backplate and a second variable capacitor with the second conductive single-crystal backplate.
A method of fabricating a dual-backplate microphone, the method comprising:
- providing a first wafer comprising a first conductive single-crystal backplate and a conductive diaphragm;
- providing a second conductive single-crystal backplate;
- and
- bonding the second conductive single-crystal backplate to the first wafer having the first conductive single-crystal backplate, such that the diaphragm is sandwiched between, but electrically isolated from, the first conductive single-crystal backplate and the second conductive single-crystal backplate;
- and
- releasing the diaphragm after the first conductive single-crystal backplate and second conductive single-crystal backplate are bonded.
A method of fabricating a dual-backplate microphone, the method comprising:
- providing a first wafer comprising a first conductive single-crystal backplate and a conductive diaphragm;
- providing a second conductive single-crystal backplate, the second conductive single-crystal backplate comprising a second wafer comprising a backplate layer, an adhesive layer and a donor layer;
- and
- bonding the second conductive single-crystal backplate to the first wafer having the first conductive single-crystal backplate, such that the diaphragm is sandwiched between, but electrically isolated from, the first conductive single-crystal backplate and the second conductive single-crystal backplate;
- and
- removing the donor layer and adhesive layer of the second wafer.
A method of fabricating a dual-backplate microphone, the method comprising:
- providing a first wafer comprising a first conductive single-crystal backplate and a conductive diaphragm;
- providing a second conductive single-crystal backplate, the second conductive single-crystal backplate comprising a second backplate layer having a first face, wherein the first face comprises one or more standoffs;
- and
- bonding the second conductive single-crystal backplate to the first wafer having the first conductive single-crystal backplate, such that the diaphragm is sandwiched between, but electrically isolated from, the first conductive single-crystal backplate and the second conductive single-crystal backplate.
Dependencies are inferred from the claim text.