Multi-functional MEMs Devices

Citation

(2004), "Multi-functional MEMs Devices", Sensor Review, Vol. 24 No. 3. https://doi.org/10.1108/sr.2004.08724cad.008

Multi-functional MEMs Devices

Multi-functional MEMs Devices

Inventor: Robert S. OkojiePatent number: US6,706,549Publication date: 16 March 2004Title: Multi-functional micro electromechanical devices and method of bulk manufacturing same

Keywords: MEMs, Patents, Manufacturing

This invention relates to micro electromechanical devices and presents a method for bulk manufacturing multi-functional SiC sensors. It enables the simultaneous fabrication of different types of sensor (flow sensors, pressure sensors, accelerometers, inertial sensors, angular rate sensors and yaw rate sensors) from the same wafer and thereby reducing the manufacturing costs. These sensors may be configured as desired by the user's specific application. For sensors requiring that the SiC substrate be pierced, the patent describes a method for employing process flow reversal whereby the metallization is applied before the recesses are etched into or through the wafer. Materials other than SiC may be used as the substrate material, including: AlN, BC, BN, and Al₂O₃ and any substrate upon which an epilayer may be grown.

The invention overcomes problems associated with conventional methods of producing pressure sensors or accelerometers, which use strain gages that have been bonded on metal diaphragms. Such designs suffer from coefficient of thermal expansion (CTE) mismatch, as they are made of materials with dissimilar properties. This leads to fatigue and early failure.