Fabrication of a high sensitivity MEMS accelerometer with symmetrical double-sided serpentine beam-mass structure

This paper reports a new high sensitivity accelerometer with symmetrical double-sided serpentine beam-mass structure and fabricated with a novel pre-buried mask etching fabrication technology. To get the symmetrical double-sided beam with defined thickness, it needs to do the photolithograph on the deep etched wafer again in the etching process in the conventional fabricating methods. But the novel fabrication technology can bury several masks in the silicon dioxide before etching and open these pre-buried masks at the defined etching depth by the etch of silicon dioxide instead of doing photolithograph again, making the fabrication process simpler and more efficient. The prototype has the performance of low noise (40 μg) and μg-level Allan deviation of bias (2.2 μg in one hour), experimentally demonstrating the effectivity of the design and the novel fabrication technology.