Surface acoustic wave device incorporating single crystal linbo.sub.3

Abstract

A surface acoustic wave device includes at least diamond, a single crystal LiNbO.sub.3 layer formed on the diamond, and an interdigital transducer formed in contact with the LiNbO.sub.3 layer and uses a surface acoustic wave (wavelength: .lambda..sub.n .mu.m) in an nth-order mode (n=1 or 2). When the thickness of the LiNbO.sub.3 layer is t.sub.1 (.mu.m), kh.sub.1 =2.pi.(t.sub.1 /.lambda..sub.n) and the cut orientation (.theta., .PHI., and .psi. represented by an Eulerian angle representation) with respect to the crystallographic fundamental coordinate system of the LiNbO.sub.3 layer are selected from values within specific ranges. Consequently, a surface acoustic wave device which increases the propagation velocity (V) of a surface acoustic wave and improves the electromechanical coupling coefficient (K.sup.2) is realized.