| 摘要 |
An elastic wave device using plate waves is provided that requires no cavity and thus can be manufactured by a simplified process and offers high mechanical strength, ease of handling, and improved temperature characteristics. An elastic wave device (1) propagating plate waves has a stack of an acoustic reflection layer (3), a piezoelectric layer (4), and IDT electrode (5) on a supporting substrate 2. The piezoelectric layer (4) is thinner than the period of the fingers of the IDT electrode (5). The acoustic reflection layer (3) has low-acoustic-impedance layers (3b, 3d, 3f, and 3h) and high-acoustic-impedance layers (3a, 3c, 3e, and 3g). The low-acoustic-impedance layers are made of SiO 2 , and the high-acoustic-impedance layers are made of at least one material selected from the group consisting of W, LiTaO 3 , Al 2 O 3 , AIN, LiNbO 3 , SiN, and ZnO. |
