Method for manufacturing a surface acoustic wave device

摘要

A method of manufacturing a surface acoustic wave device having a high electromechanical coefficient and reflection coefficient, and also having an improved frequency-temperature characteristic is achieved by forming a SiO2 film on an IDT so as to prevent cracking from occurring on a surface of the SiO2 film so that desired properties can be reliably obtained. The surface acoustic wave device includes at least one IDT, which is composed of a metal or an alloy having a density higher than that of Al and is formed on a 25° to 55° rotation-Y plate X propagation LiTaO3 substrate, and a SiO2 film disposed on the LiTaO3 substrate so as to cover the at least one IDT for improving the frequency-temperature characteristic.