DIAMOND-ZNO SURFACE ACOUSTIC WAVE DEVICE HAVING RELATIVELY THINNER ZNO PIEZOELECTRIC LAYER

摘要

The present invention directed to a SAW device comprising a diamond layer thinner ZnO layer, which can be operated at higher frequency, with superior characteristics including less energy loss. The first SAW device according to the present invention comprises a layer constitution shown in Fig. 23, wherein, for 0th mode surface acoustic wave having a wavelength .lambda., a parameter kh3 = (2.pi./.lambda.)t3 satisfies: 0.0470 0.0625, and wherein a parameter kh1 = (2r.pi./A)t1 and a parameter kh2 = (2.pi./.lambda.)t2 are given within a region A-B- C-D-E-F-A in a two-dimensional Cartesian coordinate graph having ordinate axis of the kh1 and abscissa axis of kh2, the outer edge of the region A-B-C-D-E-F-A being given by a closed chain in the Cartesian coordinate, consisting of points A, B, C, D, E, and F, and lines A-B, B-C, C-D, D-E, E-F and F-A, as shown in a two-dimensional Cartesian coordinate graph of Fig. 3.