Abstract: Regarding a boundary acoustic wave device in which at least a part of an IDT electrode is embedded in a groove disposed in a piezoelectric substrate, the acoustic velocity is increased. A boundary acoustic wave device is provided with a piezoelectric substrate, a first dielectric layer, and an IDT electrode. The surface of the piezoelectric substrate is provided with a groove. The IDT electrode is disposed at the boundary between the piezoelectric substrate and the first dielectric layer in such a way that at least a part thereof is located in the groove. In the inside of the groove, the groove angle ?, which is the size of an angle formed by an upper end portion of the inside surface of the groove with the surface of the piezoelectric substrate, is less than 90 degrees.

Abstract: Regarding a boundary acoustic wave device in which at least a part of an IDT electrode is embedded in a groove disposed in a piezoelectric substrate, the acoustic velocity is increased. A boundary acoustic wave device is provided with a piezoelectric substrate, a first dielectric layer, and an IDT electrode. The surface of the piezoelectric substrate is provided with a groove. The IDT electrode is disposed at the boundary between the piezoelectric substrate and the first dielectric layer in such a way that at least a part thereof is located in the groove. In the inside of the groove, the groove angle ?, which is the size of an angle formed by an upper end portion of the inside surface of the groove with the surface of the piezoelectric substrate, is less than 90 degrees.

Abstract: Regarding a boundary acoustic wave device in which at least a part of an IDT electrode is embedded in a groove disposed in a piezoelectric substrate, the acoustic velocity is increased. A boundary acoustic wave device is provided with a piezoelectric substrate, a first dielectric layer, and an IDT electrode. The surface of the piezoelectric substrate is provided with a groove. The IDT electrode is disposed at the boundary between the piezoelectric substrate and the first dielectric layer in such a way that at least a part thereof is located in the groove. In the inside of the groove, the groove angle ?, which is the size of an angle formed by an upper end portion of the inside surface of the groove with the surface of the piezoelectric substrate, is less than 90 degrees.

Abstract: A surface acoustic wave device including an SiO film has improved frequency temperature characteristics, prevents an increase in insertion loss, obtains a reflection coefficient of an electrode that is sufficiently high, and achieves more preferable resonant characteristics and filter characteristics. The surface acoustic wave device includes a LiNbO3 substrate having a plurality of grooves formed in an upper surface thereof, an IDT electrode primarily composed of Pt provided in the grooves, a SiO2 layer arranged so as to cover the upper surface of the LiNbO3 substrate and the IDT electrode, a surface of the SiO2 layer is planarized, a response of a Rayleigh wave is utilized, and Euler angles of the LiNbO3 substrate are in a range of (0°±5°, 208° to 228°, 0°±5°).

Abstract: A surface acoustic wave device including an SiO film has improved frequency temperature characteristics, prevents an increase in insertion loss, obtains a reflection coefficient of an electrode that is sufficiently high, and achieves more preferable resonant characteristics and filter characteristics. The surface acoustic wave device includes a LiNbO3 substrate having a plurality of grooves formed in an upper surface thereof, an IDT electrode primarily composed of Pt provided in the grooves, a SiO2 layer arranged so as to cover the upper surface of the LiNbO3 substrate and the IDT electrode, a surface of the SiO2 layer is planarized, a response of a Rayleigh wave is utilized, and Euler angles of the LiNbO3 substrate are in a range of (0°±5°, 208° to 228°, 0°±5°).

Abstract: A surface acoustic wave device includes a LiNbO3 substrate having a plurality of grooves formed in the upper surface thereof, an IDT electrode formed by filling the grooves with a metal, and a SiO2 layer arranged to cover an upper surface of the LiNbO3 substrate and the IDT electrode and having a substantially flat surface. The surface acoustic wave device uses a response of a Rayleigh wave. The LiNbO3 substrate has Euler angles in the range of (0°±5°, 180° to 247°, 0°±5°).

Abstract: A surface acoustic wave device includes a LiNbO3 substrate having a plurality of grooves formed in the upper surface thereof, an IDT electrode formed by filling the grooves with a metal, and a SiO2 layer arranged to cover an upper surface of the LiNbO3 substrate and the IDT electrode and having a substantially flat surface. The surface acoustic wave device uses a response of a Rayleigh wave. The LiNbO3 substrate has Euler angles in the range of (0°±5°, 180° to 247°, 0°±5°).