Memorias de investigación
Communications at congresses:
Sputtered AlN thin films with tilted grains for shear mode resonators applied to biosensors

Research Areas
  • Electronic technology and of the communications

Sputtered AlN is a piezoelectric material with applications in electroacoustic devices such as high frequency filters or biological sensors. For most of them, films are deposited with the c-axis of their wurtzite structure perpendicular to the surface. The most commonly-used resonator structure consists in an electrode/AlN/electrode piezoelectric capacitor acoustically isolated from the substrate by an air gap (suspended structures) or by an acoustic reflector (solidly mounted resonators). In these devices the propagating acoustic wave mode is longitudinal, that is, the movement of the material is parallel to the propagating direction, which is parallel to the c-axis. For biosensing applications, which require in-liquid operation, this mode is not suitable due to its high energy radiation to the medium, which gives rise to a reduction of the quality factor. For proper operation, shear mode resonators, where the movement of the material is perpendicular to the propagation direction and parallel to the surface, are need. To generate these modes, it is essential to create a component of the electric field perpendicular to the c-axis. The most straightforward way to do so is to deposit AlN films with grains whose c-axis is tilted with respect to the normal to the surface. To deposit such films, well-controlled directional deposition and rough substrates are needed. In this communication, we present the deposition process and material characterization of tilted grain AlN films. Bulk acoustic wave resonators, made with this material, are also presented together with their application to biosensors operating in-liquid medium. Some details about device design and operation in the detection of proteins are also included.
2016 e-MRS Fall meeting
Varsovia (Polonia)
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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: Ingeniería Electrónica