Abstract: First base layers made of TiN or TiOxNy (where, 0<x<0.2, x+y=1) and second base layers made of Cr are provided between interdigital transducer portions and a piezoelectric substrate, and accordingly, it is possible to prevent voids from being generated in the interdigital transducer portions, which improves a power resistance of the surface acoustic wave device. In addition, since it is possible to prevent the voids from being generated in the interdigital transducer portions, it is possible to suppress the resistance of the interdigital transducer portions from increasing, which can reduce the loss of power. In addition, it is also possible to reduce the variations in a serial resonance frequency and a parallel resonance frequency.

Abstract: A surface acoustic wave element having power resistance is provided. In the surface acoustic wave element, upper dispersion preventing layers and side dispersion preventing layers each made of metal nitride are provided between interdigital transducer electrode portions and an insulating layer. Further, lower dispersion preventing layers made of metal nitride are provided between the interdigital transducer electrode portions and a piezoelectric substrate. If dispersion preventing layers made of ‘metal nitride’ are provided between the interdigital transducer electrode portions and the insulating layer, even though the insulating layer is formed, it is possible to prevent voids from being generated in the interdigital transducer electrode portions, unlike a related art. Therefore, the power resistance can be improved.

Abstract: According to the method of manufacturing a surface acoustic wave device of the invention, since a conductor layer is formed on electrode sections in a state where the entire regions of inter digital transducer and reflectors are covered with an insulating film, the inter digital transducer and the reflectors are protected by the insulating film during formation of the conductor layer. As a result, it is possible to obtain a highly efficient surface acoustic wave device with no sticking of foreign matters to the inter digital transducer and the reflectors.

Abstract: First base layers made of TiN or TiOxNy (where, 0<x<0.2, x+y=1) and second base layers made of Cr are provided between interdigital transducer portions and a piezoelectric substrate, and accordingly, it is possible to prevent voids from being generated in the interdigital transducer portions, which improves a power resistance of the surface acoustic wave device. In addition, since it is possible to prevent the voids from being generated in the interdigital transducer portions, it is possible to suppress the resistance of the interdigital transducer portions from increasing, which can reduce the loss of power. In addition, it is also possible to reduce the variations in a serial resonance frequency and a parallel resonance frequency.

Abstract: According to the method of manufacturing a surface acoustic wave device of the invention, since a conductor layer is formed on electrode sections in a state where the entire regions of inter digital transducer and reflectors are covered with an insulating film, the inter digital transducer and the reflectors are protected by the insulating film during formation of the conductor layer. As a result, it is possible to obtain a highly efficient surface acoustic wave device with no sticking of foreign matters to the inter digital transducer and the reflectors.

Abstract: A surface acoustic wave element having power resistance is provided. In the surface acoustic wave element, upper dispersion preventing layers and side dispersion preventing layers each made of metal nitride are provided between interdigital transducer electrode portions and an insulating layer. Further, lower dispersion preventing layers made of metal nitride are provided between the interdigital transducer electrode portions and a piezoelectric substrate. If dispersion preventing layers made of ‘metal nitride’ are provided between the interdigital transducer electrode portions and the insulating layer, even though the insulating layer is formed, it is possible to prevent voids from being generated in the interdigital transducer electrode portions, unlike a related art. Therefore, the power resistance can be improved.

Abstract: A piezoelectric substrate and interdigital electrode portions are covered with an insulating layer with an insulating thin film interposed therebetween. The piezoelectric substrate is made of LiTaO3 and the insulating thin film and the insulating layer are made of silicon oxide. By intentionally making the upper surface of the insulating layer flat, the deterioration of propagation efficiency of surface acoustic waves can be suppressed, so that it is possible to reduce increase in insertion loss of a resonator. Since the upper surface of the insulating layer is flat, it is also possible to reduce variation in resonant frequency and anti-resonant frequency due to the temperature change of the surface acoustic wave device.