Abstract
The anisotropic materials as the acoustic wave propagating medium introduce the dependence of the phase velocity on the wave propagation direction, as opposed to the isotropic counterparts; in addition, the profile of the particle displacement components can be quite different, depending on the crystal type and propagation direction. The propagation of surface and bulk acoustic waves (SAWs and BAWs) along the (001), (111) and (110) planes of cubic SiC crystals have been studied. For specific propagation directions in these planes, slight variations in the velocity of the elastic surface waves are found. It was observed that Rayleigh-type, generalized and pseudo-surface waves can propagate at specific directions, thus confirming how the anisotropic behavior of the bare SiC substrate modifies the existence and the field profile of the SAW that propagates at its free surface. Finally, the SAW propagation along AlN/SiC-based multilayered structures is studied for the three SiC planes, different AlN piezoelectric layer thicknesses and electrical boundary conditions.
Highlights
Bulk acoustic waves (BAWs) propagating along an anisotropic medium show characteristics different as compared to the isotropic case
If the wave propagation direction coincides with the principal axis direction, three pure modes propagate having their polarization vectors parallel to the reference system axis: the longitudinal, shear horizontal and shear vertical bulk acoustic waves (LBAW, SHBAW and SVBAW)
Surface acoustic waves (SAWs) propagating in isotropic media are elliptically polarized in the sagittal plane: their phase velocity is unaffected by the propagation direction, and, the phase and group velocities coincide
Summary
Bulk acoustic waves (BAWs) propagating along an anisotropic medium show characteristics different as compared to the isotropic case. AlN, in combination with a fast substrate material such as SiC, creates new and exciting opportunities for miniaturizing, reducing power consumption, and improving the performance and functionality of many devices including sensors, actuators, radio frequency micro-electro-mechanical systems (RF MEMS) and optical arrays. Such 3C-SiC/c-AlN devices are robust, providing improved chemical stability, thermal stability, reproducibility and sensitivity compared to conventional polycrystalline piezoelectric MEMS
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
