Patent ID: 7132779

Claim:
A surface acoustic wave device comprising: an elastic substrate; a dielectric thin film provided on the elastic substrate, at least one of said elastic substrate and said dielectric thin film being made of a piezoelectric material; and at least one of an IDT electrode and a reflector electrode disposed between the elastic substrate and the dielectric thin film, said at least one of said IDT electrode and said reflector electrode including at least one region where a strip is disposed within an interval defined by approximately a half-wavelength of the surface acoustic wave in the direction of propagation of the surface acoustic wave, and said strip being used for reflection of surface acoustic waves; wherein said dielectric thin film covers the strip of said at least one of said IDT electrode and said reflector electrode, the upper surface of the dielectric thin film covering the strip protrudes with respect to a portion of the dielectric thin film where the strip is not disposed, via a slope, and the inclination angle of the slope with respect to the upper surface of the dielectric thin film overlying the strip is greater than about 30°.