Title :
Sub-μg Ultra-Low-Noise MEMS Accelerometers Based on CMOS-Compatible Piezoelectric AlN Thin Films
Author :
Gerfers, F. ; Kohlstadt, M. ; Bar, H. ; He, M.-Y. ; Manoli, Y. ; Wang, L.-P.
Author_Institution :
Intel Corp., Santa Clara
Abstract :
Piezoelectric accelerometers based on aluminum nitride thin films offer a number of advantages in microelectromechanical systems such as high signal-to-noise ratio, low dielectric loss, low power requirements and CMOS process compatibility. This paper reports the state-of-the-art piezoelectric accelerometer design with an emphasis on maximizing the sensitivity per area. The accelerometers have a novel sensing structure to increase the sensitivity without increasing the sensing area using the approach of stress concentrations. Furthermore, the sensing structure is designed to have low off-axis sensitivity and to be reliable with symmetric balanced bars between sensing beams. Experimental results confirm the significantly improved sensitivity of the accelerometers obtained with the new sensing structures. The tested charge sensitivity is 5.2pC/g and the measured total noise floor of sensor plus interface electronics is as low as 670ng/√Hz.
Keywords :
CMOS integrated circuits; accelerometers; aluminium compounds; micromechanical devices; piezoelectric devices; thin films; AlN; CMOS process compatibility; low dielectric loss; microelectromechanical systems; piezoelectric accelerometers; piezoelectric thin films; ultra-low-noise MEMS accelerometers; Accelerometers; Aluminum nitride; CMOS process; Dielectric losses; Dielectric thin films; Electronic equipment testing; Microelectromechanical systems; Micromechanical devices; Piezoelectric films; Signal to noise ratio; Accelerometers; Aluminumnitride; MEMS; Piezoelectric Thin Film; Sensitivity;
Conference_Titel :
Solid-State Sensors, Actuators and Microsystems Conference, 2007. TRANSDUCERS 2007. International
Conference_Location :
Lyon
Print_ISBN :
1-4244-0841-5
Electronic_ISBN :
1-4244-0842-3
DOI :
10.1109/SENSOR.2007.4300349