CMOS MOEMS sensor device
The present invention relates to a sensor device. More particularly, the invention relates to a CMOS-based micro-optical-electromechanical-sensor (MOEMS) device with silicon light emitting devices, silicon waveguides and silicon detectors being fabricated using current Complementary Metal Oxide Semiconductor (CMOS) technology or Silicon on Insulator (SOI) technology. According to the invention there is provided a sensor comprising: a Silicon-based light emitting structure; an integrated electro-optical mechanical interface structure that is capable to sense mechanical deflections; an integrated electronic driving and processing circuitry so as to detect physical parameters such as vibration, motion, rotation, acceleration.
1. A sensor device comprising:
A Silicon-based light emitting structure operating in avalanche breakdown mode, the light emitting structure being a SiLED and capable of transmitting light having a wavelength higher than 600 nm but lower than the absorption edge of silicon at 950 nm;
A monolithically integrated wave-guiding system integrated with the silicon light emitting structure, the wave-guiding system comprising a trench in a substrate being outlined by a thin layer of oxide and a higher refractive index material, which can be of square or circular refractive index profile so as to create either single mode or multimode optical propagation;
An interface module introducing an intensity change and/or phase change of the transmitted light;
A detector for detecting the intensity and/or phase change; and
An integrated electronic driving and processing circuitry so as to process the detector output signal, so as to sense parameters such as vibration, motion, rotation, acceleration, gas flow, gas composition or liquid flow or liquid composition or to detect optical absorption, additional wavelength added or omitted elements in gaseous or fluidic samples, wherein
the Silicon-based light emitting structure, the monolithically integrated wave-guiding system, the detector, and the integrated electronic driving and processing circuitry are integrated on a single chip.
2. The sensor as claimed in claim 1 , which is either Complementary Metal Oxide Semiconductor (CMOS) technology based or Silicon-on-insulator (SOI) based.
3. The sensor as claimed in claim 1 , further comprising additional optical filters and/or a reference optical path section so as to increase the sensitivity of the device for measurements.
4. The sensor as claimed in claim 1 , wherein light of the Silicon-based light emitting structure is emitted directional.
5. The sensor as claimed in claim 1 , wherein the wave-guiding system comprises a plurality of transparent layers with graded refractive indices.
6. The sensor as claimed in claim 1 , wherein the trench is an isolation trench in a below 0.35 μm CMOS technology.
7. The sensor as claimed in claim 1 , the wave-guiding system comprising Silicon nitride, or silicon-oxinitride or an optically transparent polymer.
8. The sensor as claimed in claim 1 , wherein the light emitting structure comprises a lateral enhanced multiplication SI LED having a highly doped region which is embedded in a region of lower doping and having a triangular tip such that a light emission zone interfaces with a core of a trench-based optical waveguide.
9. The sensor as claimed in claim 1 , wherein the detector is a p+n-well based detector with an elongated depletion layer, which is 45 degrees diagonally down into the wafer for above 600 nm wavelength detection.