Integrated resonating gyro accelerometer in a semiconductor substrate
An integrated interferometric gyroscope and accelerometer device. An example device includes a cantilever beam, a package having a post connected to one end of the beam, a piezoresistor driver, a piezoresistor sensor, and a semiconductor interferometric optical gyro. The piezoresistor driver is incorporated within the beam at a first area proximate to the post. The driver electro-thermally resonates the beam. The piezoresistor sensor is incorporated within the beam at the first area. The sensor piezoresitively senses a signal that relates to an acceleration force out-of-plane of the beam. The semiconductor interferometric optical gyro is also incorporated within the beam at a second area of the beam. The gyro senses rotational motion about an axis approximately equivalent to the acceleration force out-of-plane of the beam. The gyro includes a waveguide, a laser source and a light detector. The beam is formed from a semiconductor substrate.
1. An integrated interferometric gyroscope and accelerometer device, the device comprising:
a cantilever beam;
a package comprising a post connected to one end of the beam;
a driver incorporated within the beam at a first area proximate to the post, the driver configured to electro-thermally resonate the beam;
a sensor incorporated within the beam at the first area, the sensor configured to sense a signal that relates to an acceleration force out-of-plane of the beam; and
a semiconductor interferometric optical gyro incorporated within the beam at a second area of the beam, the gyro being incorporated to sense rotational motion about an axis approximately equivalent to a vector corresponding to the acceleration force.
2. The device of claim 1 , wherein the gyro comprises a waveguide, a light source and a light detector.
3. The device of claim 2 , wherein the beam is formed from a semiconductor substrate.
4. The device of claim 3 , wherein the semiconductor substrate is a single silicon substrate.
5. The device of claim 3 , wherein the light source is formed within a layer of the substrate.
6. The device of claim 3 , wherein the interferometric optical gyro further comprises interface electronics formed at a third area of the beam.
7. The method of claim 2 , wherein the light detector is a photo diode.
8. The device of claim 1 , further comprising a sensor package lid that is hermetically sealed with the package.
9. The device of claim 1 , wherein the driver is a piezoresistor driver and the sensor is a piezoresistor sensor.
10. A method for sensing a rotational force and an acceleration force, the method comprising:
electro-thermally resonating a cantilever beam mounted at one end to a post of a package;
sensing a signal that relates to an acceleration force out-of-plane of the beam; and
sensing rotational motion of the beam about an axis approximately equivalent to a vector corresponding to the acceleration force, wherein sensing rotational motion using a semiconductor interferometric optical gyro incorporated within the beam.
11. The method of claim 10 , wherein the gyro comprises a waveguide, a light source and a light detector.
12. The method of claim 11 , wherein the beam is formed from a semiconductor substrate.
13. The method of claim 12 , wherein the semiconductor substrate is a single silicon substrate.
14. The method of claim 12 , wherein the light source is formed within a layer of the substrate.
15. The method of claim 12 , wherein the interferometric optical gyro further comprises interface electronics formed on the beam.
16. The method of claim 11 , wherein the light detector is a photo diode.
17. The method of claim 10 , further comprising hermetically sealing the beam within the package.
18. The method of claim 10 , wherein electro-thermally resonating is performed by a piezoresistor driver and sensing the signal that relates to an acceleration force is performed by a piezoresistor sensor.