Title :
Theoretical study on SAW characteristics of layered structures including a diamond layer
Author :
Nakahata, Hideaki ; Hachigo, Akihiro ; Higaki, Kenjiro ; Fujii, Shohei ; Shikata, Shin-Ichi ; Fujimori, Naoji
Author_Institution :
Res. Labs., Sumitomo Electr. Ind. Ltd., Itami, Japan
fDate :
5/1/1995 12:00:00 AM
Abstract :
Diamond has the highest surface acoustic wave (SAW) velocity among all materials and thus can provide much advantage for fabrication of high frequency SAW devices when it is combined with a piezoelectric thin film. Basic SAW properties of layered structures consisting of a piezoelectric material layer, a diamond layer and a substrate were examined by theoretical calculation. Rayleigh mode SAW´s with large SAW velocities up to 12,000 m/s and large electro-mechanical coupling coefficients from 1 to 11% were found to propagate in ZnO/diamond/Si, LiNbO/sub 3//diamond/Si and LiTaO/sub 3//diamond/Si structures. It was also found that a SiO/sub 2//ZnO/diamond/Si structure can realize a zero temperature coefficient of frequency with a high phase velocity of 8,000-9,000 m/s and a large electro-mechanical coupling coefficient of up to 4%.<>
Keywords :
Rayleigh waves; acoustic materials; diamond; elemental semiconductors; lithium compounds; piezoelectric thin films; silicon; surface acoustic wave devices; ultrasonic velocity; zinc compounds; 12000 m/s; 8000 to 9000 m/s; LiNbO/sub 3/-C-Si; LiTaO/sub 3/-C-Si; Rayleigh mode; SAW characteristics; SAW velocity; Si; SiO/sub 2/-ZnO-C-Si; ZnO-C-Si; diamond layer; electro-mechanical coupling coefficients; high frequency SAW devices; layered structures; phase velocity; piezoelectric thin film; zero temperature coefficient; Acoustic materials; Acoustic waves; Fabrication; Frequency; Piezoelectric films; Piezoelectric materials; Substrates; Surface acoustic wave devices; Surface acoustic waves; Zinc oxide;
Journal_Title :
Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on
