	US 12,156,474 B2
	Piezoelectric device and method of manufacturing the same
Daisuke Nakamura, Ibaraki (JP); Naoki Nagaoka, Ibaraki (JP); Manami Kurose, Ibaraki (JP); and Hironobu Machinaga, Ibaraki (JP)
Assigned to NITTO DENKO CORPORATION, Ibaraki (JP)
Appl. No. 17/279,692
Filed by Nitto Denko Corporation, Ibaraki (JP)
PCT Filed Sep. 20, 2019, PCT No. PCT/JP2019/037070 § 371(c)(1), (2) Date Mar. 25, 2021, PCT Pub. No. WO2020/066930, PCT Pub. Date Apr. 2, 2020.
Claims priority of application No. 2018-185550 (JP), filed on Sep. 28, 2018; and application No. 2019-061630 (JP), filed on Mar. 27, 2019.
Prior Publication US 2022/0037580 A1, Feb. 3, 2022
Int. Cl. H01L 41/083 (2006.01); H10N 30/00 (2023.01); H10N 30/057 (2023.01); H10N 30/076 (2023.01); H10N 30/079 (2023.01); H10N 30/50 (2023.01); H10N 30/853 (2023.01)

CPC H10N 30/508 (2023.02) [H10N 30/057 (2023.02); H10N 30/076 (2023.02); H10N 30/079 (2023.02); H10N 30/708 (2024.05); H10N 30/853 (2023.02)]

11 Claims

1. A piezoelectric device comprising:

a first electrode layer;

a second electrode layer; and

a piezoelectric layer provided between the first electrode layer and the second electrode layer,

wherein the piezoelectric layer comprises a first piezoelectric film over a first surface of a substrate and a second piezoelectric film over the first piezoelectric film, the first piezoelectric film and the second piezoelectric film have a wurtzite crystal structure and have ZnO as a main component, to which one or more elements is/are added,

wherein a haze value is 3% or less, and transmittance with respect to light having a wavelength of 380 nm is 50% or more, and

wherein Si is added to the first piezoelectric film.