title: Sputtered SiO2 as low acoustic impedance material for Bragg mirror fabrication in BAW resonators.
abstract: In this paper we describe the procedure to sputter low acoustic impedance SiO(2) films to be used as a low acoustic impedance layer in Bragg mirrors for BAW resonators. The composition and structure of the material are assessed through infrared absorption spectroscopy. The acoustic properties of the films (mass density and sound velocity) are assessed through X-ray reflectometry and picosecond acoustic spectroscopy. A second measurement of the sound velocity is achieved through the analysis of the longitudinal lambda/2 resonance that appears in these silicon oxide films when used as uppermost layer of an acoustic reflector placed under an AlN-based resonator.
authors.affiliation: Grupo de Microsistemas y Materiales Electronicos of Universidad Politecnica de Madrid, Madrid, Spain. olivares@etsit.upm.es
authors.forename: Jimena
authors.initials: J
authors.lastname: Olivares
authors.forename: Enrique
authors.initials: E
authors.lastname: Wegmann
authors.forename: José
authors.initials: J
authors.lastname: Capilla
authors.forename: Enrique
authors.initials: E
authors.lastname: Iborra
authors.forename: Marta
authors.initials: M
authors.lastname: Clement
authors.forename: Lucía
authors.initials: L
authors.lastname: Vergara
authors.forename: Robert
authors.initials: R
authors.lastname: Aigner
mesh_terms: D000162:Acoustics / Q000295:instrumentation*; D017076:Computer-Aided Design; D017097:Electric Impedance; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007909:Lenses; D055617:Micro-Electrical-Mechanical Systems / Q000295:instrumentation*; D012031:Refractometry / Q000295:instrumentation*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012822:Silicon Dioxide / Q000737:chemistry*; D014159:Transducers; D014732:Vibration
chemical_list: D012822:Silicon Dioxide