Fabrication and characterization of a piezoelectric accelerometer

Zinc oxide based piezoelectric accelerometers were fabricated by bulk micromachining. A high yield was obtained in a relatively simple process sequence. For two electrode configurations a direction selectivity better than 100 was obtained for acceleration in the vertical direction and a selectivity of 3 for acceleration in the horizontal direction, respectively. The charge sensitivity in the vertical direction is better than 0.1 pC g-L and a noise level of 1× 10-4 g Hz-L/2 was estimated.