| 摘要 |
PROBLEM TO BE SOLVED: To make satisfactory the group delay time temperature characteristics of surface acoustic resonator using an La3Ga5SiO14 single crystal by setting the Euler angle of a piezoelectric substrate so as to be a special azimuth, and setting the film thickness of an interdigital transducer(IDT) so as to be a value within a specific range for the wavelength of surface acoustic waves excited on the substrate. SOLUTION: The Euler angle (ϕ,θ,ϕ) of a piezoelectric substrate is set so as to be (11 deg. to 13 deg., 152 deg. to 155 deg., 37 deg.±2 deg.) or an equivalent azimuth, and the film thickness of an IDT is set so as to be ranging from 0.005 to 0.15 for the wavelength of surface acoustic waves excited on the substrate. This surface acoustic wave resonator 1 is constituted by forming one IDT 3 on a piezoelectric substrate 2 made of an La3 Ga5SiO14 single crystal as materials and reflectors 4 on the both sides of the IDT 3. The IDT 3 is formed of electrode materials such as Al or Au, and a pair of comb- shaped electrodes 3a and 3b are arranged so that each comb-shaped parts can be faced to each other. Thus, the Euler angle and the film thickness of the electrode are optimized so that a surface acoustic wave device in which the fluctuation of frequencies is reduced can be obtained.
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