DIAMOND-ZNO SURFACE ACOUSTIC WAVE DEVICE

摘要

The present invention directed to a SAW device comprising a diamond layer a ZnO layer and an SiO2 layer, which can be operated at the frequency of 2 GHz or higher, with superior durability and less energy loss. The SAW device for 2nd mode surface acoustic wave of a wavelength .lambda. (.mu.m) according to the present invention comprises: (i) a diamond layer, (ii) a ZnO layer formed on the diamond layer, the ZnO layer having a thickness tz, (iii) an interdigital transducer (IDT) formed over the ZnO layer, and (iv) a SiO2 layer formed over the interdigital transducer onto the ZnO layer, the SiO2 layer having a thickness of tz; wherein parameters khz=(2.pi./.lambda.)tz and khz=(2.pi./.lambda.)tz are given within a region A-B-C-D-E-F-G-H-I-J-K-L-M-N-O-P-Q-R-A in a two-dimensional Cartesian coordinate graph having abscissa axis of khz and ordinate axis of khz, the outer edge of the region A-B-C-D-E-F-G-H-I-J-K-L-M-N-O-P-Q-R- A being given by a closed chain in the Cartesian coordinate, consisting of points A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q and R and lines A-B, B-C, C-D, D-E, E-F, F-G, G-H, H-I, I-J, J-K, K-L, L-M, M-N, N-O, O-P, P-Q, Q-R and R-A, as shown in Fig. 1.