Design, fabrication and characterization of a zinc oxide thin-film piezoelectric accelerometer

Conventionally manufactured accelerometers based on piezoelectric lead zirconate titanate (PZT) have been used for decades, but integration issues hinder their application in micro-electro-mechanical systems (MEMS). Compared to PZT, zinc oxide (ZnO) has lower piezoelectricity and is not an attractive material for use in traditional bulky accelerometers due to its low sensitivity. However, ZnO has excellent compatibility with MEMS processing techniques, and furthermore, sensitivity can be enhanced by MEMS miniaturization. In this paper, we report the development of a micromachined ZnO piezoelectric thin-film accelerometer that demonstrates the feasibility of both easy integration and high sensitivity.