US5225286A
Expired / Lapsed
US
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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 13:39
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)
US4112193A
Cited
JPS6057959A
Cited
US4734340A
Cited
US4961994A
Cited
US4973526A
Cited
US5064729A
Cited
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 |