Design of sub-1g microelectromechanical systems accelerometers

This paper presents a design of microelectromechanical systems (MEMS) accelerometers for sensing sub-1g (g = 9.8 m/s2) acceleration. The accelerometer has a high-density proof mass to suppress the Brownian noise that dominates the output noise of the sensor. The low-temperature (<400 °C) process enables to integrate the accelerometer on the sensing complementary metal-oxide semiconductor circuit by electroplating of gold; a proof mass of 1020 μm × 1020 μm in area with the thickness of 12 μm has been found to suppress the measured noise floor to 0.78 μg/Hz at 300 K, which is nearly one order of magnitude smaller than those of the conventional MEMS accelerometers made of silicon.