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US5235233A
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Surface acoustic wave device
Assignee: RR Elektronische Geraete GmbH and Co KG
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Filing: 1992-06-22
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Granted: 1993-08-10
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Expires: 2012-06-22
Abstract
Abstract IDT electrodes (4) are provided in a two-layer structure of a diamond crystal (2) in an AlN thin film (3) so that a third Rayleigh wave or a Sezawa wave propagates in the two-layer structure. Or else, a third Rayleigh wave propagates in a substrate of a three-layer structure wherein a SiO2 film is provided between a diamond crystal (2) or an AlN thin film (3). SAW devices which have high electromechanical coupling coefficients and high phase velocities are obtained based on those structures. A SAW device in which a third Rayleigh wave propagates is suitable for a narrowband timing tank filter or bandpass filter which is used in a microwave region of several GHz to 20 GHz. A SAW device in which a Sezawa wave propagates is suitable for a wideband voltage-controlled oscillator or a wide bandpass filter which is used in a wide frequency range from the VHF-band to the UHF-band.
Inventors
- 👤 Shin-ichi Yamamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:00
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/02; H03H9/02535; H03H9/02543; H03H9/02582; H03H9/0296; H03H9/02976
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
25 words
A surface acoustic wave device for propagating surface acoustic waves, comprising: a diamond crystal; and an aluminum nitride thin film formed on said diamond crystal.
Claim 2
Dependent Claim
25 words
A surface acoustic wave device for propagating surface acoustic waves, comprising: a diamond crystal; and an aluminum nitride thin film formed on said diamond crystal.
Claim 3
Dependent Claim
23 words
A surface acoustic wave device as set forth in claim 1, further comprising: interdigital transducer electrodes formed on said aluminum nitride thin film.
Claim 4
Dependent Claim
51 words
A surface acoustic wave device as set forth in claim 2, wherein said aluminum nitride thin film has a thickness H selected to satisfy 3.5≦kH≦5.0 where k is a wave number, and so that a third Rayleigh surface acoustic wave propagates in said diamond crystal and said aluminum nitride thin film.
Claim 5
Dependent Claim
50 words
A surface acoustic wave device as set forth in claim 2, wherein said aluminum nitride thin film has a thickness H selected to satisfy 1.1≦kH≦6.0 where k is a wave number, and so that a Sezawa surface acoustic wave propagates in said diamond crystal and said aluminum nitride thin film.
Claim 6
Dependent Claim
30 words
A surface acoustic wave device as set forth in claim 1, wherein said diamond crystal includes: a single-crystal semiconductor substrate; and a diamond crystal thin film formed on said substrate.
Claim 7
Dependent Claim
23 words
A surface acoustic wave device as set forth in claim 5, further comprising: interdigital transducer electrodes formed on said aluminum nitride thin film.
Claim 8
Dependent Claim
75 words
A surface acoustic wave device as set forth in claim 6, wherein said aluminum nitride thin film has a thickness H selected to satisfy 3.5≦kH≦5.0 where k is a wave number, and wherein said diamond crystal thin film and the thickness H of said aluminum nitride thin film have the relationship of D≧4H and so that a third Rayleigh surface acoustic wave propagates in said diamond crystal thin film and said aluminum nitride thin film.
Claim 9
Dependent Claim
74 words
A surface acoustic wave device as set forth in claim 6, wherein said aluminum nitride thin film has a thickness H selected to satisfy 1.1≦kH≦6.0 where k is a wave number, and wherein said diamond crystal thin film and the thickness H of said aluminum nitride thin film have the relationship of D≧5H and so that a Sezawa surface acoustic wave propagates in said diamond crystal thin film and said aluminum nitride thin film.
Claim 10
Dependent Claim
32 words
A surface acoustic wave device, comprising: a diamond crystal; a silicon dioxide thin film formed on said diamond crystal; and an aluminum nitride thin film formed on said silicon dioxide thin film.
Claim 11
Dependent Claim
32 words
A surface acoustic wave device, comprising: a diamond crystal; a silicon dioxide thin film formed on said diamond crystal; and an aluminum nitride thin film formed on said silicon dioxide thin film.
Claim 12
Dependent Claim
48 words
A surface acoustic wave device as set forth in claim 9, wherein said aluminum nitride thin film has a thickness H, and wherein said silicon dioxide thin film has a thickness T selected to satisfy 0.01H≦T≦0.1H where H is the thickness H of said aluminum nitride thin film.
Claim 13
Dependent Claim
52 words
A surface acoustic wave device as set forth in claim 10, further comprising: interdigital transducer electrodes formed on said aluminum nitride thin film which has the thickness H selected to satisfy 3.2≦kH≦4.7 where k is a wave number, and so that a third Rayleigh surface acoustic wave propagates in said three-layer structure.
Claim 14
Dependent Claim
65 words
A surface acoustic wave device as set forth in claim 10, further comprising: interdigital transducer electrodes formed on the interface between said aluminum nitride thin film and said silicon dioxide thin film, and wherein said aluminum nitride thin film has thickness H which satisfies 3.7≦kH≦4.7 where k is a wave number, and so that a third Rayleigh surface acoustic wave propagates in said three-layer structure.
Claim 15
Dependent Claim
31 words
A surface acoustic wave device as set forth in claim 9, wherein said diamond crystal includes: a single-crystal semiconductor substrate; and diamond crystal thin film formed on said single-crystal semiconductor substrate.
Claim 16
Dependent Claim
33 words
A surface acoustic wave device for propagating surface acoustic waves, comprising: a diamond crystal; an ground electrode formed on said diamond crystal; and an aluminum nitride thin film formed on said ground electrode.
Claim 17
Dependent Claim
33 words
A surface acoustic wave device for propagating surface acoustic waves, comprising: a diamond crystal; an ground electrode formed on said diamond crystal; and an aluminum nitride thin film formed on said ground electrode.
Claim 18
Dependent Claim
23 words
A surface acoustic wave device as set forth in claim 14, further comprising: interdigital transducer electrodes formed on said aluminum nitride thin film.
Claim 19
Dependent Claim
46 words
A surface acoustic wave device as set forth in claim 15, wherein said aluminum nitride thin film has a thickness H selected to satisfy 3.5≦kH≦5.0 where k is a wave number, and so that a third Rayleigh surface acoustic wave propagates in said acoustic wave device.
Claim 20
Dependent Claim
45 words
A surface acoustic wave device as set forth in claim 15, wherein said aluminum nitride thin film has a thickness H selected to satisfy 1.1≦kH≦6.0 where k is a wave number, and so that a Sezawa surface acoustic wave propagates in said acoustic wave device.
Claim 21
Dependent Claim
30 words
A surface acoustic wave device as set forth in claim 14, wherein said diamond crystal includes: a single-crystal semiconductor substrate; and a diamond crystal thin film formed on said substrate.
Claim 22
Dependent Claim
23 words
A surface acoustic wave device as set forth in claim 18, further comprising: interdigital transducer electrodes formed on said aluminum nitride thin film.
Claim 23
Dependent Claim
75 words
A surface acoustic wave device as set forth in claim 19, wherein said aluminum nitride thin film has a thickness H selected to satisfy 3.5≦kH≦5.0 where k is a wave number, and wherein said diamond crystal thin film and the thickness H of said aluminum nitride thin film have the relationship of D≧4H and so that a third Rayleigh surface acoustic wave propagates in said diamond crystal thin film and said aluminum nitride thin film.
Claim 24
Dependent Claim
74 words
A surface acoustic wave device as set forth in claim 19, wherein said aluminum nitride thin film has a thickness H selected to satisfy 1.1≦kH≦6.0 where k is a wave number, and wherein said diamond crystal thin film and the thickness H of said aluminum nitride thin film have the relationship of D≧5H and so that a Sezawa surface acoustic wave propagates in said diamond crystal thin film and said aluminum nitride thin film.
Claim 25
Dependent Claim
48 words
A surface acoustic wave device as set forth in claim 13, wherein said aluminum nitride thin film has a thickness H, and wherein said silicon dioxide thin film has a thickness T selected to satisfy 0.01H≦T≦0.1H where H is the thickness H of said aluminum nitride thin film.
Claim 26
Dependent Claim
52 words
A surface acoustic wave device as set forth in claim 22, further comprising: interdigital transducer electrodes formed on said aluminum nitride thin film which has the thickness H selected to satisfy 3.2≦kH≦4.7 where k is a wave number, and so that a third Rayleigh surface acoustic wave propagates in said three-layer structure.
Claim 27
Dependent Claim
65 words
A surface acoustic wave device as set forth in claim 22, further comprising: interdigital transducer electrodes formed on the interface between said aluminum nitride thin film and said silicon dioxide thin film, and wherein said aluminum nitride thin film has thickness H which satisfies 3.7≦kH≦4.7 where k is a wave number, and so that a third Rayleigh surface acoustic wave propagates in said three-layer structure.
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