Published October 2004
| Version v1
Journal article
Anisotropic propagation of surface acoustic waves on nitride layers
Contributors
Others:
- Departamento de Ingeniería Electrónica and ISOM (ETSI Telecomunicacion) ; Universidad Politécnica de Madrid (UPM)-Ciudad Universitaria
- Centre de recherche sur l'hétéroepitaxie et ses applications (CRHEA) ; Université Nice Sophia Antipolis (1965 - 2019) (UNS) ; COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA)
Description
The anisotropic propagation of surface acoustic modes in GaN and AlN induced by the -sapphire substrate is presented. In the GaN case, the slow acoustic propagation velocity of GaN compared with sapphire leads to guided modes in the overlayer, which propagate at higher velocities but are more attenuated than the Rayleigh mode. Above the transonic state, pseudo-SAW modes are observed, some of them with low insertion losses. In contrast, only the Rayleigh mode is observed in AlN filters due to its higher acoustic propagation velocity with respect to sapphire. The difference in the crystal structure of the sapphire and the nitrides induces a dependence of the sound velocity of all the modes, and hence their frequency, on the propagation direction. The simulations show very good agreement with the experimental data for both nitride/sapphire structures when the anisotropy induced by the substrate is taken into account.
Abstract
International audienceAdditional details
Identifiers
- URL
- https://hal.archives-ouvertes.fr/hal-02906531
- URN
- urn:oai:HAL:hal-02906531v1
Origin repository
- Origin repository
- UNICA