A NEW HIGH-PERFORMANCE SURFACE-MICROMACHINED TUNNELING ACCELEROMETER FABRICATED USING NANOLITHOGRAPHY

We have fabricated a new class of high-performance tunneling accelerom eters using surface micromachining. The accelerometer structures are f abricated on the surface of a single silicon wafer and consist of a si ngle 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-mu m-long cantilever devices are 8.3x10(-4) and 8.5x10(-5) g/Hz(1/2) at 500 Hz, respectively. The devices are operate d in a force rebalance feedback mode using a low noise automatic servo -control circuit, providing a dynamic range of over 10(4) g. This new accelerometer technology provides devices with extremely high sensitiv ity, high bandwidth, and wide dynamic range, in an ultracompact, low-c ost package that is easily integrated with silicon control electronics . (C) 1996 American Vacuum Society.