Patent ID: 7956512

Claim:
A surface acoustic wave device comprising: a piezoelectric substrate including a plurality of grooves provided in an upper surface thereof and being made of an LiNbO 3 substrate; and an IDT including a plurality of electrode fingers made of a metal material which is filled in the plurality of grooves in the upper surface of the piezoelectric substrate; wherein the metal material is Pt or W or an alloy primarily including at least one of Pt or W; and when a wavelength of a surface acoustic wave is represented by λ, an electrode thickness of the IDT and θ of Euler angles (0°±10°, θ, 0°±10°) of the LiNbO 3 substrate are one of combinations shown in Table 1: TABLE 1 ELECTRODE ELECTRODE EULER MATERIAL THICKNESS ANGLE θ Pt 0.04λ ≦ Pt ≦ 0.08λ 70° ≦ θ ≦ 134° W 0.02λ ≦ W ≦ 0.04λ 70° ≦ θ ≦ 139° W 0.04λ < W ≦ 0.08λ 74° ≦ θ ≦ 139°.