Patent US5225286A successfully refreshed from Google Patents.
US5225286A
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Dielectric film
Assignee: Denso Corp
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Filing: 1992-06-12
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Granted: 1993-07-06
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Expires: 2012-06-12
Abstract
Abstract A tantalum oxide dielectric film includes tantalum oxide (Ta2O5) as a major component, and at least one oxide selected from the group consisting of yttrium oxide (Y2O3), tungsten oxide (WO3) and niobium oxide (Nb2O5). This dielectric film exhibits a remarkably improved dielectric constant and insulation property because it is a composite oxide film in which Ta2O5 is compounded with Y2O3, WO3 or Nb2O5. For example, when the dielectric film is used as a capacitor film, the capacitor film exhibits a figure of merit, i.e., a product of a dielectric constant and an insulation property, approximately twice the silicon oxide (SiO2) film which is used widely for the purpose at present.
Inventors
- 👤 Hisayoshi Fujikawa
- 👤 Yasunori Taga
- 👤 Makio Iida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 22:18
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/60; H10D64/66; H10D64/68; H10D64/681; H10D64/685; H10D1/00; H10D1/60; H10D1/68; H10D64/691; Y; Y10; Y10S; Y10S428/00; Y10S428/901; Y10S428/917; Y10T; Y10T428/00; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
81 words
A tantalum oxide dielectric film, consisting essentially of: tantalum oxide (Ta 2 O 5 ) as a major component; and one oxide selected from the group consisting of yttrium oxide (Y 2 O 3 ) and tungsten oxide (WO 3 ), wherein said tantalum oxide dielectric film contains yttrium or tungsten in an amount of 8 to 32 atomic % or 2 to 15 atomic %, respectively, relative to the sum of tantalum and yttrium/tungsten therein taken as 100 atomic %.
Claim 2
Dependent Claim
81 words
A tantalum oxide dielectric film, consisting essentially of: tantalum oxide (Ta 2 O 5 ) as a major component; and one oxide selected from the group consisting of yttrium oxide (Y 2 O 3 ) and tungsten oxide (WO 3 ), wherein said tantalum oxide dielectric film contains yttrium or tungsten in an amount of 8 to 32 atomic % or 2 to 15 atomic %, respectively, relative to the sum of tantalum and yttrium/tungsten therein taken as 100 atomic %.
Claim 3
Dependent Claim
40 words
The tantalum oxide dielectric film according to claim 1, wherein said tantalum oxide dielectric film includes tungsten in an amount of 2 to 4 atomic % when the sum of tantalum and tungsten therein is taken as 100 atomic %.
Claim 4
Dependent Claim
19 words
The tantalum oxide dielectric film according to claim 1, wherein a thickness thereof is not more than 4000 angstroms.
Claim 5
Dependent Claim
22 words
The tantalum oxide dielectric film according to claim 3, wherein a thickness thereof falls in a range of 100 to 1000 angstroms.
Claim 6
Dependent Claim
22 words
The tantalum oxide dielectric film according to claim 4, wherein said thickness thereof falls in a range of 700 to 1000 angstroms.
Claim 7
Dependent Claim
21 words
The tantalum oxide dielectric film according to claim 1, wherein said tantalum oxide dielectric film is employed in an LSI circuit.
Claim 8
Dependent Claim
22 words
The tantalum oxide dielectric film according to claim 1, wherein said tantalum oxide dielectric film is employed in an EL display device.
Claim 9
Dependent Claim
22 words
The tantalum oxide dielectric film according to claim 1, wherein said tantalum oxide dielectric film is employed in an EC display device.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-07-05 | 1997-01-04 | 1997-07-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-07-05 | 2001-01-04 | 2001-07-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-07-05 | 2005-01-04 | 2005-07-06 | $7700.00 | Window Closed / Lapsed |