Measurement of ultrasonic surface wave velocities in silicon crystals and its comparison with finite element analysis

Abstract

The velocities of leaky surface acoustic waves (SAWs) have been measured using a large-aperture line-focused transducer for three silicon single crystals (namely, Si-100, Si-110, and Si-111). While rotating the specimen, velocities were measured as a function of propagation direction. The slowness curves of the SAWs show good agreement with the crystal structures of the specimens. Finite element method (FEM) simulation has also been carried out for silicon crystals and the results were compared with the measurement results. The FEM results can explain the measured ones. This method has high potential for determining crystal structures.

Longitudinal leaky surface acoustic wave with low attenuation on LiTaO3 or LiNbO3 thin plate bonded to quartz substrate

“…For these reasons, SAW propagation modes have been studied by focusing on the material and on substrate structures with various combinations of materials. [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] For example, towards realizing a highly stable TCF for an LSAW, temperature-compensated SAW filters with an LT substrate bonded to a sapphire support substrate have achieved practical use. 21) Recently, an "incredible high-performance SAW (I.H.P.…”

3D FEM simulation of SAW resonators using hierarchical cascading technique and general purpose graphic processing unit

“…[5][6][7][8][9] The finite element method (FEM) [10][11][12] has been used to find appropriate optimal device structures and determine the parameters necessary for device simulation. [13][14][15][16][17][18][19][20][21] It was believed that the conventional FEM was not applicable for three-dimensional (3D) simulation of whole SAW device structures because of required memory size and computation time.…”

High coupling and highly stable leaky surface acoustic waves on LiTaO3 thin plate bonded to quartz substrate

“…In particular, to obtain a high frequency, a large electromechanical coupling factor (K 2 ), a large quality (Q) factor, and a small temperature coefficient of frequency (TCF), SAW propagation modes have been studied by focusing on the material of the substrate used. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] Leaky surface acoustic waves (LSAWs) and longitudinal-type LSAWs (LLSAWs) have a higher phase velocity than Rayleigh-type SAWs (R-SAW), 18) which is advantageous for application to high-frequency SAW devices. [19][20][21] However, they have inherent attenuation because they lose energy by continuously radiating bulk waves into the substrate.…”