Propagation properties of leaky surface acoustic wave on water-loaded LiTaO₃/quartz bonded structure

Abstract

Recently, bonded structures such as LiTaO3/quartz structures have been attracting attention as a means of obtaining high-performance surface acoustic wave (SAW) devices. To investigate the possibility of evaluating the acoustical loss in such bonded structures by subtracting the calculated leakage loss into the water from the measured normalized attenuation factor, propagation properties such as the velocity and normalized attenuation factor of leaky SAWs on a water-loaded 36°YX-LiTaO3/AT0°X-quartz bonded structure were investigated using a line-focus-beam ultrasonic material characterization system and were found to be in good agreement with the calculated values for both the 0°X and 90°X propagation directions.

Analysis of longitudinal leaky surface acoustic waves on quartz thin plate bonded to similar-material substrate

“…Recently, many studies have been reported related to high-performance SAW devices. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] The SAW propagation modes suitable for high-frequency devices include a shear horizontal (SH) leaky SAW (LSAW) and a longitudinal LSAW (LLSAW) with relatively high phase velocity. However, an LSAW has inherent attenuation because it propagates while radiating a shear vertical (SV) bulk wave into the substrate.…”

“…Recently, to satisfy such requirements, high-performance dissimilar-material bonded structures have been developed. 1,[7][8][9][10][11][12][13][14][15][16][17][18][19][20] For instance, bonded structures comprising an LT or LN thin plate with a thickness of less than one wavelength and a Qz support substrate have been developed and the LSAWs and LLSAWs in these structures have been investigated. [13][14][15][16][17][18][19] A high-frequency resonator with an LN thin plate and a multilayered acoustic reflector with a SiO 2 /Pt layer have been realized by utilizing LLSAW with high velocity.…”

“…1,[7][8][9][10][11][12][13][14][15][16][17][18][19][20] For instance, bonded structures comprising an LT or LN thin plate with a thickness of less than one wavelength and a Qz support substrate have been developed and the LSAWs and LLSAWs in these structures have been investigated. [13][14][15][16][17][18][19] A high-frequency resonator with an LN thin plate and a multilayered acoustic reflector with a SiO 2 /Pt layer have been realized by utilizing LLSAW with high velocity. 1) It is difficult to bond of dissimilar-material structures owing to the difference between the linear expansion coefficients of the different materials.…”

Evaluation of bulk and surface acoustic waves propagation properties of (K,Na)NbO3 films deposited by hydrothermal synthesis or RF magnetron sputtering methods

“…Since it is difficult to satisfy the above requirements with only a single crystal substrate, SAW and BAW propagation structures composed of several materials to obtain the desired properties have been actively developed. For instance, SAW propagation properties with high-performance on composite structures comprising a piezoelectric crystal thin plate bonded to a support substrate, such as sapphire, 2) Si, [3][4][5][6][7][8] quartz, [9][10][11][12][13][14][15][16][17][18] and a similar material to the thin plate, 19,20) have been developed.…”

Analysis of leaky surface acoustic waves on quartz thin plates bonded to similar-material substrate

“…In particular, highperformance SAW devices have been achieved using dissimilar-material bonded structures. 4,5,[7][8][9]13,14,[17][18][19][20][21][22][23] As an example, an "incredibly high-performance SAW resonator" with a large Q factor and small temperature coefficient of frequency (TCF) was fabricated by combining LT and a multilayer substrate. 17,21) A high-frequency resonator with an LN thin plate and a multilayered acoustic reflector with a SiO 2 /Pt layer have been realized by utilizing LLSAW with high velocity.…”