Sputtered A1N Thin Films for Piezoelectric MEMS Devices

• Published in: 2006 5th IEEE Conference on Sensors pp. 10 - 13
• Main Authors: Wang, Li-Peng, Ginsburg, Eyal, Gerfers, Friedel, Samara-Rubio, Dean, Weinfeld, Boaz, Ma, Qing, Rao, Valluri, He, Ming Yuan
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.10.2006
• Subjects: Accelerometers; Material properties; Microelectromechanical devices; Micromechanical devices; Piezoelectric devices; Piezoelectric effect; Piezoelectric films; Sputtering; Testing; Thin film devices
• DOI: 10.1109/ICSENS.2007.355705
• ISBN: 1424403758; 9781424403752
• ISSN: 1930-0395

Piezoelectric films have been demonstrated to be attractive for micromechanical systems (MEMS) devices. Among the piezoelectric films used, AlN film has been less explored. In this study, AlN resonators and accelerometers, utilizing longitudinal and transverse piezoelectric effects respectively, were demonstrated. Resonators with Q of 1000 and electromechanical coupling (k t 2 ) of 6.5% were achieved at ~2 GHz. Accelerometers were fabricated and tested with charge sensitivities ranging between 0.06 to 0.45 pC/g depending on device designs. Important material properties of sputtered AlN films - C 33 of 435 GPa, e 33 of 1.55 C/m 2 , and e 31 of -0.58 C/m 2 - were extracted by fitting finite element analysis (FEA) simulated values to measured results.