US 11,923,820 B2
Acoustic wave device
Tetsuya Kimura, Nagaokakyo (JP); and Shou Nagatomo, Nagaokakyo (JP)
Assigned to MURATA MANUFACTURING CO., LTD., Kyoto (JP)
Filed by Murata Manufacturing Co., Ltd., Nagaokakyo (JP)
Filed on Jun. 11, 2021, as Appl. No. 17/345,238.
Application 17/345,238 is a continuation of application No. PCT/JP2019/047903, filed on Dec. 6, 2019.
Claims priority of application No. 2018-233575 (JP), filed on Dec. 13, 2018.
Prior Publication US 2021/0305964 A1, Sep. 30, 2021
Int. Cl. H03H 9/02 (2006.01)
CPC H03H 9/02015 (2013.01) [H03H 9/02157 (2013.01); H03H 9/02228 (2013.01); H03H 9/02574 (2013.01)] 15 Claims
OG exemplary drawing
 
1. An acoustic wave device comprising:
a support substrate;
a piezoelectric layer provided directly or indirectly on the support substrate; and
an IDT electrode including a plurality of electrode fingers and provided on a main surface of the piezoelectric layer; wherein
a thickness of the piezoelectric layer is about 1λ or less when a wavelength of an acoustic wave determined by an electrode finger period of the IDT electrode is defined as λ;
the piezoelectric layer is made of lithium tantalate or lithium niobate;
Euler angles of the piezoelectric layer are an orientation determined in any of ranges of, or an orientation crystallographically equivalent to Euler angles determined in any of ranges of (about 90°±5°, about 90°±5°, about 40°±20°), (about 0°±5°, about 35°±20°, about 90°±20°), and (about 0°±5°, about 85°±20°, about 90°±20°); and
the support substrate is an A-plane sapphire substrate.