US4495431A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low reflectivity surface-mounted electrodes on semiconductive saw devices
Assignee: RTX Corp
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Filing: 1983-08-22
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Granted: 1985-01-22
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Expires: 2003-08-22
Abstract
Abstract Low reflectivity electrodes (2, 7) are provided on semiconductive and piezoelectric substrates (1, 6) including a layer (3, 9) of gold-germanium mixture and a layer (5, 8) of raw gold, or only a gold-germanium mixture (10), the total germanium content of the electrode comprising approximately 2%-3% of the total gold and germanium content of the electrode, and the thickness of the electrode being on the order of 1% of the acoustic wavelength.
Inventors
- 👤 Thomas W. Grudkowski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:12
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/02; H03H9/125; H03H9/145; H03H9/14538; H03H9/02535; H03H9/02543; H03H9/02566; H03H9/02818; H03H9/02858; H03H9/02881
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
60 words
A surface acoustic wave device comprising: a substrate of semiconducting and piezoelectric material; and metallic electrodes formed on the surface of said substrate, characterized by: said electrodes comprising gold and germanium with germanium consisting of about 2%-3% of the total gold and germanium, said electrodes having thickness which is a small fraction of the design acoustic wavelength of the device.
Claim 2
Dependent Claim
60 words
A surface acoustic wave device comprising: a substrate of semiconducting and piezoelectric material; and metallic electrodes formed on the surface of said substrate, characterized by: said electrodes comprising gold and germanium with germanium consisting of about 2%-3% of the total gold and germanium, said electrodes having thickness which is a small fraction of the design acoustic wavelength of the device.
Claim 3
Dependent Claim
26 words
A surface acoustic wave device according to claim 1 further characterized by said electrodes comprising a layer of raw gold and a layer of gold-germanium mixture.
Claim 4
Dependent Claim
28 words
A surface acoustic wave device according to claim 2 wherein said electrode comprises a layer of nickel disposed between said layer of gold and said layer of gold-germanium.
Claim 5
Dependent Claim
25 words
A surface acoustic wave device according to claim 1 further characterized by: said electrode comprising said gold layer disposed adjacent the surface of said substrate.
Claim 6
Dependent Claim
25 words
A surface acoustic wave device according to claim 1 further characterized by: said electrode including said gold-germanium layer disposed adjacent the surface of said substrate.
Claim 7
Dependent Claim
22 words
A surface acoustic wave device according to claim 5 wherein said gold-germanium layer is alloyed, thereby providing ohmic contact with said substrate.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-01-22 | 1988-07-23 | 1989-01-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-01-22 | 1992-07-23 | 1993-01-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-01-22 | 1996-07-23 | 1997-01-22 | $7700.00 | Window Closed / Lapsed |