Micromachined sensor and actuator research at Sandia's Microelectronics Development Laboratory

摘要

An overview of the major sensor and actuator projects using the micromachining capabilities of the Microelectronics Development Laboratory at Sandia National Laboratories are presented. Development efforts are underway for a variety of micromechanical devices and control electronics for those devices. Our efforts are concentrated in the area of surface micromachining. Pressure sensors based on silicon nitride diaphragms and hot polysilicon filaments for calorimetric gas sensing have been developed. Accelerometers based upon high-aspect ratio surface micromachining are being developed. Actuation mechanisms employing either electrostatic or steam power are being combined with a three-level active (plus an additional passive level) polysilicon surface micromachining process to couple these actuators to external devices. The results of efforts toward integration of micromechanics with the driving electronics for actuators or the amplification/signal processing electronics for sensors is also described. This effort includes a CMOS-first, tungsten metallization process to allow the CMOS electronics to withstand high-temperature micromechanical processing. Also, a unique micromechanics-first approach is being pursued in which the micromechanical devices are embedded below the surface of the starting material for the CMOS.