US5122923A
Expired / Lapsed
US
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Thin-film capacitors and process for manufacturing the same
Assignee: NEC Corp
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Filing: 1990-08-30
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Granted: 1992-06-16
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Expires: 2010-08-30
Abstract
Abstract A thin-film capacitor comprises a substrate, a first electrode, of polycrystalline silicon, a second electrode, a dielectric, and a third electrode such as aluminum in the structure stacked in sequence from bottom to top. The second electrode directly on which the dielectric layer is formed is made from a member selected from the group consisting of ruthenium, ruthenium oxide, ruthenium silicide, rhenium, rhenium oxide, rhemium silicide, osmium, osmium oxide, osmium silicide, rhodium, rhodium oxide, rhodium silicide, iridium, iridium oxide and iridium silicide.
Inventors
- 👤 Shogo Matsubara
- 👤 Yoichi Miyasaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 02:02
CPC Classifications
H; H10; H10B; H10B53/00; H10D; H10D1/00; H10D1/60; H10D1/68; H10D1/692; H10D1/682; Y; Y10; Y10T; Y10T29/00; Y10T29/43; Y10T29/435
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
90 words
A thin-film capacitor comprising: a first electrode layer consisting essentially of polycrystalline silicon; a second electrode layer formed on the first electrode layer, the second electrode layer consisting essentially of a member selected from the group consisting of ruthenium, ruthenium oxide, ruthenium silicide, rhenium, rhenium oxide, rhenium silicide, osmium, osmium oxide, osmium silicide, rhodium, rhodium oxide, rhodium silicide, iridium, iridium oxide and iridium silicide; a dielectric layer consisting essentially of an oxide ferroelectric material formed on said second electrode layer; and a third electrode layer formed on said dielectric layer.
Claim 2
Dependent Claim
90 words
A thin-film capacitor comprising: a first electrode layer consisting essentially of polycrystalline silicon; a second electrode layer formed on the first electrode layer, the second electrode layer consisting essentially of a member selected from the group consisting of ruthenium, ruthenium oxide, ruthenium silicide, rhenium, rhenium oxide, rhenium silicide, osmium, osmium oxide, osmium silicide, rhodium, rhodium oxide, rhodium silicide, iridium, iridium oxide and iridium silicide; a dielectric layer consisting essentially of an oxide ferroelectric material formed on said second electrode layer; and a third electrode layer formed on said dielectric layer.
Claim 3
Dependent Claim
34 words
A thin-film capacitor as recited in claim 1, wherein said oxide ferroelectric is a member selected from the group consisting of perovskite type oxides, ilmenite oxides and Bi 4 Ti 3 O 12 .
Claim 4
Dependent Claim
36 words
A thin-film capacitor as recited in claim 1, wherein said oxide ferroelectric is a member selected from the group consisting of BaTiO 3 , SrTiO 3 , PbTiO 3 , PbZrO 3 and solid solutions thereof.
Claim 5
Dependent Claim
25 words
A thin-film capacitor as recited in claim 1, wherein a silicon dioxide layer is not present between said dielectric layer and the second electrode layer.
Claim 6
Dependent Claim
25 words
A thin-film capacitor as recited in claim 1, wherein said dielectric layer has a dielectric constant which is independent of thickness of the dielectric layer.
Claim 7
Dependent Claim
45 words
A thin-film capacitor as recited in claim 1, further comprising a substrate, one surface of the first electrode layer being in contact with the substrate and an opposite surface of the first electrode layer being in contact with one surface of the second electrode layer.
Claim 8
Dependent Claim
14 words
A thin-film capacitor as recited in claim 6, wherein the substrate comprises silicon dioxide.
Claim 9
Dependent Claim
23 words
A thin-film capacitor as recited in claim 1, wherein the second electrode has a surface roughness of no greater than about 50 Å.
Claim 10
Dependent Claim
19 words
A thin-film capacitor as recited in claim 1, wherein the third electrode layer consists of a layer of aluminum.
Claim 11
Dependent Claim
25 words
A thin-film capacitor as recited in claim 9, wherein one surface of the aluminum layer is in contact with one surface of the dielectric layer.
Claim 12
Dependent Claim
19 words
A thin-film capacitor as recited in claim 1, wherein the first electrode layer consists essentially of doped polycrystalline silicon.
Claim 13
Dependent Claim
17 words
A thin-film capacitor as recited in claim 11, wherein the first electrode layer is doped with arsenic.
Claim 14
Dependent Claim
17 words
A thin-film capacitor as recited in claim 11, wherein the first electrode layer is doped with phosphorous.
Claim 15
Dependent Claim
22 words
A thin-film capacitor as recited in claim 1, wherein the second electrode consists essentially of the rhenium, rhenium oxide or rhenium silicide.
Claim 16
Dependent Claim
27 words
A thin-film capacitor as recited in claim 1, wherein the second electrode consists essentially of the ruthenium silicide, rhenium silicide, osmium silicide, rhodium silicide or iridium silicide.
Claim 17
Dependent Claim
96 words
A process of manufacturing thin-film capacitors comprising the steps of: forming a first electrode layer consisting essentially of polycrystalline silicon; forming a second electrode layer on the first electrode layer, the second electrode layer consisting essentially of a member selected from the group consisting of ruthenium, ruthenium oxide, ruthenium silicide, rhenium, rhenium oxide, rhenium silicide, osmium, osmium oxide, osmium silicide, rhodium, rhodium oxide, rhodium silicide, iridium, iridium oxide and iridium silicide; forming a dielectric layer consisting essentially of an oxide ferroelectric on the second electrode layer; and forming a third electrode layer on said dielectric layer.
Claim 18
Dependent Claim
96 words
A process of manufacturing thin-film capacitors comprising the steps of: forming a first electrode layer consisting essentially of polycrystalline silicon; forming a second electrode layer on the first electrode layer, the second electrode layer consisting essentially of a member selected from the group consisting of ruthenium, ruthenium oxide, ruthenium silicide, rhenium, rhenium oxide, rhenium silicide, osmium, osmium oxide, osmium silicide, rhodium, rhodium oxide, rhodium silicide, iridium, iridium oxide and iridium silicide; forming a dielectric layer consisting essentially of an oxide ferroelectric on the second electrode layer; and forming a third electrode layer on said dielectric layer.
Claim 19
Dependent Claim
37 words
A process of manufacturing a thin-film capacitor as recited in claim 16, wherein said oxide ferroelectric is a member selected from the group consisting of perovskite oxides, ilmenite oxides, and Bi 4 Ti 3 O 12 .
Claim 20
Dependent Claim
40 words
A process of fabricating a thin-film capacitor as recited in claim 16, wherein said oxide ferroelectric is a member selected from the group consisting of BaTiO 3 , SrTiO 3 , PbTiO 3 , PbZrO 3 and solid solutions thereof.
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) | 1995-06-16 | 1995-12-16 | 1996-06-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-06-16 | 1999-12-16 | 2000-06-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-06-16 | 2003-12-16 | 2004-06-16 | $7700.00 | Window Closed / Lapsed |