Sensor protective coating
A microelectromechanical system (MEMS) sensor device includes a substrate, a support structure supported by the substrate, a membrane supported by the support structure and spaced from the substrate, and a polymer layer covering the membrane.
1. A microelectromechanical system (MEMS) sensor device comprising:
a substrate;
a support structure supported by the substrate;
a membrane supported by the support structure and spaced from the substrate;
a polymer layer covering the membrane; and
a dielectric layer that laterally surrounds the membrane and the support structure, wherein the dielectric layer establishes a hermetically sealed cavity between the membrane and the substrate.
2. The MEMS sensor device of claim 1 , wherein the polymer layer covers the dielectric layer.
3. The MEMS sensor device of claim 1 , further comprising a reference cell covered by the dielectric layer so that ambient pressure does not deflect a membrane of the reference cell.
4. The MEMS sensor device of claim 1 , wherein the sensor device is not enclosed by a cap.
5. The MEMS sensor device of claim 1 , further comprising a bond pad supported by the substrate, wherein the polymer layer is patterned to not cover the bond pad.
6. The MEMS sensor device of claim 1 , wherein the polymer layer comprises a photoresist material.
7. The MEMS sensor device of claim 1 , wherein the polymer layer comprises a parylene material or a polyimide material.
8. The MEMS sensor device of claim 1 , further comprising a reference cell completely covered by the dielectric layer.
9. The MEMS sensor device of claim 8 , wherein the polymer layer covers the reference cell.
10. A microelectromechanical system (MEMS) sensor device comprising:
a substrate;
a support structure supported by the substrate;
a membrane supported by the support structure and spaced from the substrate, the membrane having a periphery;
a dielectric layer disposed along the periphery of the membrane to define an opening in the dielectric layer over the membrane; and
a polymer layer disposed in the opening and covering the membrane;
wherein the dielectric layer establishes a hermetically sealed cavity between the membrane and the substrate.
11. The MEMS sensor device of claim 10 , wherein the polymer layer covers the dielectric layer.
12. The MEMS sensor device of claim 10 , wherein the dielectric layer laterally surrounds the membrane and the support structure.
13. The MEMS sensor device of claim 10 , further comprising a reference cell covered by the dielectric layer so that ambient pressure does not deflect a membrane of the reference cell.
14. The MEMS sensor device of claim 10 , further comprising a reference cell completely covered by the dielectric layer.
15. A microelectromechanical system (MEMS) sensor device comprising:
a substrate;
a support structure supported by the substrate;
a membrane supported by the support structure and spaced from the substrate by a gap, the membrane having a periphery;
a dielectric layer disposed along the periphery of the membrane to seal the gap, the dielectric layer having an opening over the membrane; and
a polymer layer disposed in the opening;
wherein the polymer layer is in contact with the membrane and the dielectric layer to cover the membrane and the dielectric layer, and
wherein the dielectric layer establishes a hermetically sealed cavity between the membrane and the substrate.
16. The MEMS sensor device of claim 15 , wherein the dielectric layer laterally surrounds the membrane and the support structure.
17. The MEMS sensor device of claim 15 , wherein the polymer layer comprises a photoresist material.
18. The MEMS sensor device of claim 15 , wherein the polymer layer comprises a parylene material or a polyimide material.
19. The MEMS sensor device of claim 15 , further comprising a reference cell completely covered by the dielectric layer.