Patent US5936831A successfully refreshed from Google Patents.
US5936831A
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Thin film tantalum oxide capacitors and resulting product
Assignee: Nokia of America Corp
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Filing: 1997-03-06
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Granted: 1999-08-10
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Expires: 2017-03-06
Abstract
Abstract In accordance with the invention, a thin film capacitor including a dielectric of nitrogen or silicon-doped tantalum oxide and at least one electrode including chromium. Preferably the capacitor is fabricated by anodically oxidizing TaN x or Ta 2 Si and forming a Cr counterelectrode. The method is fully compatible with MCM processing. It produces anodic Ta 2 O 5 capacitors having exceptionally low leakage currents (<1 nA/cm 2 at 10 V), high breakdown fields (>4 MV/cm) and high capacitance densities (70 nF/cm 2 ). The devices are stable at 350° C. with excellent capacitor properties and are particularly useful as thin film capacitors of large area (>1 mm 2 ).
Inventors
- 👤 Ratnaji Rao Kola
- 👤 King Lien Tai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 22:24
CPC Classifications
H; H01; H01G; H01G4/00; H01G4/002; H01G4/018; H01G4/06; H01G4/08; H01G4/12; H01G4/1209; H01G4/1254; H10; H10D; H10D1/00; H10D1/60; H10D1/68; H01G4/005; H01G4/008; H01G4/228; H10D1/682; H10D1/684; H10P; H10P14/00; H10P14/60; H10P14/63; H10P14/6302; H10P14/6304; H10P14/6314; H10P14/69; H10P14/692; H10P14/6938; H10P14/6939; H10P14/69393
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
69 words
A thin film tantalum oxide capacitor comprising: a substrate-supported first electrode comprising TaN x , where x denotes the atomic ratio of N; a dielectric layer comprising Ta 2 O 5 N y , where y denotes the atomic ratio of N, having an N content of at least 20 atomic % disposed on said TaN x ; and a second electrode comprising chromium disposed on said dielectric layer.
Claim 2
Dependent Claim
69 words
A thin film tantalum oxide capacitor comprising: a substrate-supported first electrode comprising TaN x , where x denotes the atomic ratio of N; a dielectric layer comprising Ta 2 O 5 N y , where y denotes the atomic ratio of N, having an N content of at least 20 atomic % disposed on said TaN x ; and a second electrode comprising chromium disposed on said dielectric layer.
Claim 3
Dependent Claim
15 words
The capacitor of claim 1 wherein said substrate comprises silicon having a silicon oxide surface.
Claim 4
Dependent Claim
13 words
The capacitor of claim 1 wherein said substrate comprises an insulating ceramic material.
Claim 5
Dependent Claim
20 words
The capacitor of claim 1 wherein said first electrode is a composite layer comprising aluminum and said TaN x .
Claim 6
Dependent Claim
15 words
The capacitor of claim 1 wherein said dielectric layer comprises anodically oxidized TaN x .
Claim 7
Dependent Claim
26 words
The capacitor of claim 1 wherein said second electrode is a composite layer comprising chromium and copper, said chromium disposed between said copper and said dielectric.
Claim 8
Dependent Claim
26 words
The capacitor of claim 1 wherein said second electrode is a composite layer comprising chromium and aluminum, said chromium disposed between said aluminum and said dielectric.
Claim 9
Dependent Claim
18 words
The capacitor of claim 1 wherein said capacitor has an area in excess of 1 mm 2 .
References Cited (Backward Citations)
US5264728A
Cited
US5696017A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-08-09 | 2003-02-08 | 2003-08-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-08-09 | 2007-02-08 | 2007-08-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-08-09 | 2011-02-08 | 2011-08-10 | $7700.00 | Window Closed / Lapsed |