Bulk acoustic wave resonator based sensor
An integrated circuit is disclosed. The integrated circuit comprises a silicon substrate, a sensor comprising a bulk acoustic wave resonator and an acoustic mirror disposed between the bulk acoustic wave resonator and the substrate, and a CMOS circuit supported by substrate and operatively connected to the sensor.
1. A system comprising
a device that includes:
a silicon substrate;
a sensor comprising:
a first bulk acoustic wave resonator; and
a first acoustic mirror disposed between the bulk acoustic wave resonator and the substrate;
a heater disposed between the first acoustic mirror and the substrate;
a CMOS circuit supported by the substrate and operatively connected to the sensor; and
a controller operatively connected to the device and configured to receive signals from the device and/or to provide control signals to the device, the controller arranged to cause heating of the heater to greater than 100° C.
2. A system according to claim 1 , wherein the device comprises:
CMOS process-defined layers,
wherein the CMOS process-defined layers include the acoustic mirror.
3. A system according to claim 1 , wherein the heater comprises a loop of conductive material.
4. A system according to claim 1 , wherein the device further comprises:
a temperature sensor disposed between the acoustic mirror and the substrate.
5. A system according to claim 1 , wherein the device further comprises:
a reference sensor comprising:
a second bulk acoustic wave resonator; and
a second acoustic mirror disposed between the bulk acoustic wave resonator and the substrate.
6. A system according to claim 1 , wherein the silicon substrate includes a hole through the substrate so as to cause the sensor to be suspended over the hole.
7. A system according to claim 1 , wherein the device is a sensor.
8. A system according to claim 1 , wherein the device is a gas and/or particle(s) sensor.
9. A system according to claim 1 , wherein the device is an integrated circuit.
10. A system according to claim 1 , wherein the device is an integrated device.
11. A method of operating the system according to claim 1 , the method comprising:
the CMOS circuit driving the sensor and measuring signals from the sensor.
12. A method according to claim 11 , wherein the device comprises a heater and wherein the method further comprises:
modulating current through the heater so as to modulate temperature of the sensor.
13. A method of fabricating the system according to claim 1 , the method comprising:
fabricating CMOS-compatible structures using CMOS-compatible materials during a CMOS fabrication phase on a silicon substrate; and
fabricating non-CMOS structures using non-CMOS-compatible materials during a post CMOS fabrication phase after the CMOS fabrication phase;
wherein fabricating the CMOS-compatible structures includes fabricating the acoustic mirror and the CMOS circuit, wherein fabricating the non-CMOS-compatible structures includes fabricating the bulk acoustic wave resonator.
14. The method of claim 13 , wherein fabricating the non-CMOS-compatible structures includes fabricating an air gap in the substrate to form a membrane, the bulk acoustic wave resonator being disposed on the membrane.
15. The method of claim 13 , wherein fabricating the CMOS-compatible structures includes fabricating a heater disposed between the acoustic mirror and the substrate.
16. The method of claim 15 , wherein the heater comprises a loop of conductive material.
17. The method of claim 13 , wherein fabricating the CMOS-compatible structures includes fabricating a temperature sensor disposed between the acoustic mirror and the substrate.