This study describes the numerical implementation of accurate and fully coupled physical models in order to investigate the sensitivity of Surface Acoustic Wave (SAW) devices using the magnetoelastic interaction with an external magnetic field. The model was first validated using experimental data previously published by Kadota et al., obtained with SAW resonators based on quartz substrates and nickel InterDigital Transducers (IDTs). The model was then used to optimize the geometry of a new magnetostrictive-piezoelectric layered structure (Ni/ZnO/IDT/LiNbO3), regarding its sensitivity to the magnetic field intensity. The optimized structure was designed and fabricated and experimental results show a good correlation with the numerical modeling. Simulations also show that if alumina is used instead of ZnO, the Ni/Al2O3/IDT/LiNbO3 structure exhibits a sensitivity that is 9 times higher than the one based on ZnO.

In this work, AlN films were deposited on silicon substrates buffered by epitaxial AlN thin film for surface acoustic wave (SAW) applications. The films were deposited by dc magnetron sputtering (dcMS) and high power impulse magnetron sputtering (HiPIMS) deposition techniques. The structural properties of AlN films were investigated using X-ray diffraction (XRD), Raman spectroscopy and atomic force microscopy. In both cases of films deposited by dcMS and HiPIMS, the XRD results showed that the obtained films are oriented, with a full width at half maximum rocking curves of around 1°. Raman spectroscopy revealed higher residual stress relaxation in the AlN epilayers grown by HiPIMS compared to AlN grown by dcMS, highlighted by a blue shift in the E2(high) Raman mode. The SAW measurements indicated an insertion loss of AlN/Si -SAW devices of about 53 and 35 dB for the AlN films deposited by dcMS and HiPIMS respectively. The relation between the 2 structural properties of AlN and the characteristics of AlN-SAW devices were correlated and discussed.

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