US 11,539,345 B2 · Surface acoustic wave device and method for manufacturing the same

Abstract

A surface acoustic wave device includes a piezoelectric single crystal substrate and an electrode. The piezoelectric single crystal substrate is made of LiTaO3 or LiNbO3. The electrode includes a titanium film formed on the piezoelectric single crystal substrate and an aluminum film or a film containing aluminum as a main component. The aluminum film or the film is formed on the titanium film. The aluminum film or the film containing aluminum as the main component is a twin crystal film or a single crystal film, the aluminum film or the film has a (111) plane that is non-parallel to a surface of the piezoelectric single crystal substrate with an angle θ, and the aluminum film or the film has a [−1, 1, 0] direction parallel to an X-direction of a crystallographic axis of the piezoelectric single crystal substrate.

Claims12

Dependent claims

A surface acoustic wave device comprising:

a piezoelectric single crystal substrate made of LiTaO3 or LiNbO3;
and
an electrode that includes a titanium film deposited on the piezoelectric single crystal substrate and an aluminum film or a film containing aluminum as a main component, the aluminum film or the film being deposited on the titanium film, wherein
the aluminum film or the film containing aluminum as the main component is a twin crystal film or a single crystal film, the aluminum film or the film has a (111) plane that is non-parallel to a surface of the piezoelectric single crystal substrate with an angle θ, and the aluminum film or the film has a [−1, 1, 0] direction parallel to an X-direction of a crystallographic axis of the piezoelectric single crystal substrate,
wherein the angle θ is in a range of −1 degrees to −2.5 degrees.

2 more elements

A method for manufacturing a surface acoustic wave device, comprising:

forming a titanium film on a LiTaO3 or LiNbO3 piezoelectric single crystal substrate of 36 to 50 degree rotated Y-cut;
and
forming an aluminum film or a film containing aluminum as a main component on the titanium film, the aluminum film or the film being a twin crystal film or a single crystal film, the aluminum film or the film having a (111) plane that is non-parallel to a surface of the piezoelectric single crystal substrate with an angle θ, and the aluminum film or the film having a [−1, 1, 0] direction parallel to an X-direction of a crystallographic axis of the piezoelectric single crystal substrate, wherein
the titanium film is formed such that the titanium film has a deposition rate and a film thickness configured to form the aluminum film or the film containing aluminum as the main component, and
wherein the angle θ is in a range of −1 degrees to −2.5 degrees.

2 more elements

Dependencies are inferred from the claim text.

Surface acoustic wave device and method for manufacturing the same

Life of this patent

Surface acoustic wave device and method for manufacturing the same

Life of this patent

Abstract

Claims12