Analysis of Longitudinal Leaky SAW on LiNbO₃ Thin Plate/Amorphous Layer/Quartz Structure

Low-Residual-Stress Amorphous Film for LiTaO₃/Quartz or LiNbO₃/Quartz Bonding toward 5G Surface Acoustic Wave Devices

“…[3,4] Thus, the SAW performance depends on the piezoelectric substrate material and the IDT pattern pitch. The requirements for 5G SAW devices are (1) a large SAW velocity (v  6,000 m/s), [14] However, the actual measured TCF value in that work was less than the calculated value of the simulations, where the disparity of results is presumed to be caused by residual stress in the bonding interface. [15] In this report, we studied various deposition methods of…”

Analysis of leaky surface acoustic wave characteristics propagating on high piezoelectric ScAlN film/high velocity quartz substrate

“…2(b), the LSAWs on the AT-cut quartz substrate, which is one of rotated Y-cut quartz, around ψ = 0°and 90°h as higher phase velocity than that in the X-cut, Y-cut, and Z-cut quartz substrate. In LSAW and LLSAW on thin piezoelectric plate or ScAlN film/quartz, [9][10][11][12][13]35) K 2 of the layered structure SAW devices strongly depend on those of piezoelectric layers, whereas K 2 of quartz substrates, which are significantly smaller than those of thin piezoelectric plate and ScAlN film, contribute little to K 2 of the layered structure. On the other hand, quartz substrates with high velocity are required to concentrate SAW at the piezoelectric layer and to suppress shear bulk wave radiation into the substrate.…”

“…In contrast, we experimentally and theoretically demonstrated that LSAW and LLSAW on an LiNbO 3 or LiTaO 3 thin piezoelectric plates bonded to high velocity sapphire or quartz substrates possess high phase velocity, high coupling, low attenuation, and high temperature stability. [8][9][10][11][12][13] In these layered structure SAW resonators, the LSAWs or LLSAWs are concentrated at the piezoelectric thin plate, and the bulk wave radiations to the substrate are suppressed. Similarly, several researchers have reported the improvement of performance in various type SAW resonators with piezoelectric thin plates/quartz substrates.…”

Analysis of longitudinal leaky surface acoustic waves on LiNbO3/amorphous layer/quartz structure

“…24,25) For a such an LN/amorphous layer/quartz substrate structure, we calculated the propagation properties of an LLSAW including attenuation and K 2 , and we also simulated the Q factors in its resonance properties. 26,27) In this paper, we investigated the propagation and resonance characteristics of LLSAW on LN/amorphous layer/ quartz substrate structures theoretically in more detail. The amorphous film thickness dependence of the attenuation was added to the propagation characteristics in Refs.…”