EP0313025A2
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Surface acoustic wave device
Assignee: Sanyo Electric Co Ltd
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Filing: 1988-10-19
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Granted: —
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Expires: 2008-10-19
Abstract
Abstract A surface acoustic wave device having a single-crystal aluminum nitride film wherein when the direction of propagation of the surface acoustic wave is expressed by (λ,µ,ϑ) according to the Euler angle notation, ϑ is set to 90 degrees, λ to a desired angle, and µ to an angle in the range of 30 to 150 degrees. In a surface acoustic wave device having a c-axis-oriented aluminum nitride film, the direction of c-axis orientation of the piezoelectric film is inclined within a plane containing the direction of propagation of the surface acoustic wave and perpendicular to the surface of the piezoelectric film at an angle in the range of about ±30 degrees to about ±150 degrees with respect to a normal to the piezoelectric film. The devices are 1.122% in maximum coupling coefficient.
Inventors
- 👤 Kenichi Shibata
- 👤 Toshiaki Yokoo
- 👤 Kousuke Takeuchi
- 👤 Toshiharu Tanaka
- 👤 Maruo Kamino
- 👤 Seiji Nishikawa
- 👤 Shoichi Nakano
- 👤 Yukinori Kuwano
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 14:08
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/02; H03H9/02535; H03H9/02543; H03H9/02574
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
66 words
A surface acoustic wave device having a single crystal aluminum nitride film as a piezoelectric film, characterized in that when the direction of propagation of the surface acoustic wave is expressed by (λ,µ,90) according to the Euler angle notation, λ is set to an angle in the range of 0 to 180 degress, and µ to an angle in the range of 30 to 150 degrees.
Claim 2
Dependent Claim
66 words
A surface acoustic wave device having a single crystal aluminum nitride film as a piezoelectric film, characterized in that when the direction of propagation of the surface acoustic wave is expressed by (λ,µ,90) according to the Euler angle notation, λ is set to an angle in the range of 0 to 180 degress, and µ to an angle in the range of 30 to 150 degrees.
Claim 3
Dependent Claim
19 words
A device as defined in claim 1 wherein µ is set to about 56 degrees or about 124 degrees.
Claim 4
Dependent Claim
60 words
A device as defined in claim 1 wherein the single crystal aluminum nitride film is formed on a substrate and has a thickness corresponding to length several times as long as a wavelength of the surface acoustic wave, the aluminum nitride film being provided on the surface thereof with a transmitting electrode and a receiving electrode opposed to each other.
Claim 5
Dependent Claim
47 words
A device as defined in claim 1 wherein the single crystal aluminum nitride film is in the form of a panel at least about 50 µm in thickness and is provided on the surface thereof with a transmitting electrode and a receiving electrode opposed to each other.
Claim 6
Dependent Claim
72 words
A surface acoustic wave device having a c-axis-oriented aluminum nitride film as a piezoelectric film, characterized in that the direction of c-axis orientation of the piezoelectric film is inclined within a plane containing the direction of propagation of the surface acoustic wave and perpendicular to the surface of the piezoelectric film at an angle in the range of ±30 degrees to ±150 degrees with respect to a normal to the piezoelectric film.
Claim 7
Dependent Claim
72 words
A surface acoustic wave device having a c-axis-oriented aluminum nitride film as a piezoelectric film, characterized in that the direction of c-axis orientation of the piezoelectric film is inclined within a plane containing the direction of propagation of the surface acoustic wave and perpendicular to the surface of the piezoelectric film at an angle in the range of ±30 degrees to ±150 degrees with respect to a normal to the piezoelectric film.
Claim 8
Dependent Claim
33 words
A device as defined in claim 5 wherein the angle between the normal to the piezoelectric film and the direction of c-axis orientation is set to about ±56 degrees or about ±124 degrees.
Claim 9
Dependent Claim
59 words
A device as defined in claim 5 wherein the c-axis-oriented aluminum nitride film is formed on a substrate and has a thickness corresponding to length several times as long as a wavelength of the surface acoustic wave, the aluminum nitride film being provided on the surface thereof with a transmitting electrode and a receiving electrode opposed to each other.
Claim 10
Dependent Claim
45 words
A device as defined in claim 5 wherein the c-axis-oriented aluminum nitride film is in the form of a panel at least 50 µm in thickness and is provided on the surface thereof with a transmitting electrode and a receiving electrode opposed to each other.
References Cited (Backward Citations)
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