Memorias de investigación
Communications at congresses:
On the Lateral Excitation Of Shear Modes in AlN Layered Resonators
Year:2012
Research Areas
  • Electronic technology and of the communications
Information
Abstract
In this paper we describe the fabrication and frequency characterization of different structures intended for the lateral excitation of shear modes in AlN c-axis-oriented films, which are at the same time designed to minimize the excitation of longitudinal modes. Laterally excited resonators were built on partially metallic (SiO2, W) and insulating (SiOC, Si3N4) acoustic mirrors built on silicon substrates, and on insulating mirrors (SiO2, TaOx) built on insulating glass plates. TiOx seed layers were used to stimulate the growth of highly c-axis oriented AlN films, which was confirmed by XRD and SAW measurements. Coplanar Mo electrodes of different geometries were defined on top of the AlN films to excite the shear modes. All the structures analyzed displayed a clear longitudinal mode, corresponding to an acoustic velocity of 11000 m/s, but a null or extremely weak shear response corresponding to a sound velocity of around 6350 m/s. The simulation of the frequency response based on Mason?s model confirms that the shear resonance is extremely weak. The observed longitudinal modes are attributed either to the field applied between the electrodes and a conductive plane (metallic layer or Si substrate) or to the electric field parallel to the c-axis in the edges of the electrodes or in tilted grains. The low excitation of shear modes is attributed to the very low values of electric field strength parallel to the surface
International
Si
Congress
International Ultrasonics Symposium
960
Place
Dresde, Alemania
Reviewers
Si
ISBN/ISSN
978-1-4673-4562-0
Start Date
07/10/2013
End Date
10/10/2013
From page
535
To page
538
2012 IEEE International Ultrasonics Symposium Proceedings
Participants
Research Group, Departaments and Institutes related
  • Creador: Grupo de Investigación: Microsistemas y Materiales Electrónicos
  • Centro o Instituto I+D+i: Centro de Materiales y Dispositivos Avanzados para Tecnologías de Información y Comunicaciones
  • Departamento: Tecnología Fotónica y Bioingeniería
  • Departamento: Tecnología Electrónica