A Z-axis differential capacitive SOI accelerometer with vertical comb electrodes

This paper describes a differentially detecting capacitive Z-axis SOI accelerometer using a set of vertical comb electrodes. The device structure has only one silicon layer and there are no lower or upper electrodes. Z-axis acceleration was differentially detected by using a set of newly proposed vertical comb electrodes of different movable and fixed heights. The sensing area was 1.1 mm×1.1 mm×15 μm. The performance of the accelerometer was calculated and measured experimentally to determine its linear capacitance change and voltage output against input acceleration. The measured capacitance sensitivity and its linearity were 1.1 fF/G and 0.21%, respectively.