Surface acoustic wave device

摘要

Disclosed herein is a surface acoustic wave device employing diamond, which has an operation frequency in a range of several hundred MHz to several GHz, a high propagation velocity and a large electromechanical coefficient. This surface acoustic wave comprises a substrate, a diamond layer which is formed on the substrate, a ZnO layer which is formed on the diamond layer, and interdigital electrodes which are formed on the ZnO layer, and utilizes a second order mode of a surface acoustic wave which is excited in a structure satisfying (2(pi).H/(lambda))=0.9 to 2.3 where H represents the thickness of the ZnO layer and (lambda) represents the wavelength of the surface acoustic wave. This surface acoustic wave device can be used in an extremely high frequency range, whereby the same is applicable to a resonator, a delay line, a signal processing device, a convolver, a correlator or the like in addition to a filter.