Integrating diverse sensors in a single semiconductor device

1. A method of manufacturing a sensor system comprising:

forming a first structure having a substrate layer and a first sensor, the first sensor being positioned on a first side of the substrate layer;

bonding a cap structure over the first sensor on the first side of the substrate layer;

depositing a first dielectric layer over the cap structure;

after bonding the cap structure and depositing the first dielectric layer, fabricating a second sensor on the first dielectric layer, wherein the second sensor includes components that would be damaged at a temperature that is used to bond the cap structure to the first side of the substrate layer.

2. A method as claimed in claim 1 further comprising:

forming a first through silicon via (TSV) in the cap structure, wherein the first TSV is coupled to conduct signals from the first sensor;

forming an electrically conductive interconnect on the cap structure, wherein the electrically conductive interconnect is in contact with the first TSV.

3. A method as claimed in claim 2 further comprising depositing additional dielectric layers on the first dielectric layer as the second sensor is formed.

4. A method as claimed in claim 3 further comprising:

forming a second TSV in the first dielectric layer and the additional dielectric layers, wherein the second TSV is in contact with the electrically conductive interconnect on the cap structure;

forming an electrically conductive contact on a top dielectric layer of the additional dielectric layers in contact with the second TSV.

5. A method as claimed in claim 4 further comprising:

forming an electrically conductive contact on the second sensor to conduct signals from the second sensor.

6. A method as claimed in claim 1 wherein the bonding operation produces a hermetically sealed cavity in which the first sensor is located.

7. A method as claimed in claim 1 wherein the first sensor is one of a group consisting of: a microelectromechanical sensor (MEMS), a transducer, an inertial sensor, a resonator, a pressure sensor, an accelerometer, a gyroscope, and a microphone.

8. A method as claimed in claim 1 wherein the second sensor is a magnetic field sensor.

9. A method as claimed in claim 2 wherein the conductive interconnect on the cap structure is a part of a redistribution layer.

10. A method as claimed in claim 1 wherein the cap structure includes Application Specific Integrated Circuitry (ASIC) configured to drive the first and/or second sensors.

11. A method of making a multi-sensor device comprising:

fabricating a micro-electromechanical system (MEMS) sensor;

bonding a cap structure over the MEMS sensor to form a hermetically sealed cavity for the MEMS sensor, wherein the cap structure includes a dielectric layer and integrated circuitry formed in a wafer;

forming a through-silicon via (TSV) in the cap structure;

forming a redistribution layer on an external surface of the wafer, wherein an interconnect of the redistribution layer is in contact with the TSV in the cap structure;

depositing an oxide isolation layer over the redistribution layer and portions of the external surface of the wafer that are not covered by the redistribution layer; and

fabricating a magnetic field sensor on the oxide isolation layer.

12. A method as claimed in claim 11 further comprising:

forming additional oxide isolation layers on the oxide isolation layer as the magnetic field sensor is fabricated.

13. A method as claimed in claim 11 wherein:

the cap structure is bonded over the MEMS sensor at a temperature greater than 300 degrees C.

14. A method as claimed in claim 11 wherein the MEMS sensor is one of a group consisting of: a transducer, an inertial sensor, a resonator, a pressure sensor, an accelerometer, a gyroscope, and a microphone.

15. A method as claimed in claim 11 wherein the magnetic field sensor is a magnetic tunnel junction sensor.