Low Loss Al_0.7Sc_0.3N Thin Film Acoustic Delay Lines

Theoretical and Experimental Study of High‐Electromechanical‐Coupling Surface Acoustic Wave Resonators Based on A‐Plane (112¯0)$\left(\right. 11 \overset{\cdot}{2} 0 \left.\right)$ Al0.56Sc0.44N Films

“…The quality factor was evaluated by the Q m method using Equation (5). Δf À3 dB is the inverse relative peak width at À3 dB of the real part of Y 11 .…”

“…[ 1,2 ] Micro electro mechanical systems devices based on AlScN, such as bulk acoustic wave resonators, surface acoustic wave (SAW) devices, piezoelectric micromachined ultrasonic transducers, Lamb wave resonators, etc., have been extensively studied and have made significant progress. [ 3–7 ] The improvement of performance for these devices is mainly attributed to the significant increase in piezoelectric coefficient d 33 of the material when AlN is doped with Sc element ( d 33 is 5.5 pC/N for AlN, while it is 27.6 pC/N for Al 0.57 Sc 0.43 N [ 8 ] ). Since acoustic waves propagate along the surface for SAW devices, the effective coupling coefficient () is greatly affected by d 31 , but not by d 33 .…”

Spurious-Free Shear Horizontal Wave Resonators Based on 36Y-Cut LiNbO3 Thin Film

“…Many piezoelectric devices have been investigated, such as surface acoustic wave (SAW) devices, thin-film bulk acoustic resonators (FBARs), and laterally vibrating resonators (LVRs). In recent decades, these resonators, which are based on different kinds of piezoelectric material, including aluminum nitride (AlN) [8,9], lead zirconate titanate (PZT) [10,11], doped AlN [12][13][14][15], and lithium niobate (LiNbO 3 ) [16][17][18], have attracted wide research interest. Among these platforms, AlN FBARs have demonstrated 7% k 2 t [19], but it is challenging to implement multiple wide resonant frequencies on the same chip with FBARs because of the thickness extensional mode.…”

Characterization of Ferroelectric Al0.7Sc0.3N Thin Film on Pt and Mo Electrodes

“…Aluminum nitride (AlN) thin films have a relatively high acoustic phase velocity, low acoustic wave loss, considerable piezoelectric coupling constant, and a coefficient of thermal expansion similar to that of Si and GaAs. These unique properties of AlN films make them widely used in mechanical, microelectronic, optical, MEMS transducers, surface wave devices (SAWs) and high-frequency broadband RF filters in the communication front-end [ 9 , 10 ]. AlN thin film is a III-V group semiconductor with a Wurtzite-type structure, and possesses polarization (N-polar and metal-polar) along the c-axis due to the separation of aluminum and nitrogen atoms in each plane under certain stress conditions [ 8 ].…”