| 摘要 |
Provided is an elastic wave device that is capable of higher sound velocity, and is also resistant to an effect of a response by another mode that is spurious. The elastic wave device (1) comprises a lithium niobate film (5) and uses an SH-type surface wave. Said elastic wave device (1) is provided with: a support substrate (2); a high sound velocity film (3) formed on the support substrate (2); a low sound velocity film (4) layered on the high sound velocity film (3); the lithium niobate film (5), which is layered on the low sound velocity film (4); and an IDT electrode (6) formed on one surface of the lithium niobate film (5). The sound velocity of a bulk wave propagated in said high sound velocity film (3) is higher than the sound velocity of an elastic wave propagated in the lithium niobate film (5). The sound velocity of a bulk wave propagated in said low sound velocity film (4) is lower than the sound velocity of a bulk wave propagated in the lithium niobate film (5). In said elastic wave device (1), theta is in the range 0°-8° and 57°-180° when the Euler angles of the lithium niobate film (5) are (0° ± 5°, theta, 0°). |
