A new high-performance surface-micromachined tunneling accelerometer fabricated using nanolithography

Abstract

We have fabricated a new class of high-performance tunneling accelerometers using surface micromachining. The accelerometer structures are fabricated on the surface of a single silicon wafer and consist of a single cantilevered beam with electrostatic deflection electrodes and a sub-100-nm-diam tunneling tip underneath. The noise level resolutions in air of 100- and 250-μm-long cantilever devices are 8.3×10−4 and 8.5×10−5 g/Hz1/2 at 500 Hz, respectively. The devices are operated in a force rebalance feedback mode using a low noise automatic servo-control circuit, providing a dynamic range of over 104 g. This new accelerometer technology provides devices with extremely high sensitivity, high bandwidth, and wide dynamic range, in an ultracompact, low-cost package that is easily integrated with silicon control electronics.