US5142437A
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US
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Conducting electrode layers for ferroelectric capacitors in integrated circuits and method
Assignee: Ramtron International Corp
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Filing: 1991-06-13
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Granted: 1992-08-25
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Expires: 2011-06-13
Abstract
Abstract A ferroelectric capacitor for an integrated circuit includes a stack formed by a layer of a noble metal, a layer of a conducting oxide, a layer of a ferroelectric material, another layer of a conducting oxide and another layer of a noble metal. The capacitor can also have another layer of conducting oxide located over the top layer of noble metal and below the first layer of the noble metal. A method of forming the same through establishing one layer over the other and annealing each layer is also disclosed.
Inventors
- 👤 Lee Kammerdiner
- 👤 Maria Huffman
- 👤 Manoochehr Golabi-Khoozani
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 12:28
CPC Classifications
H; H01; H01G; H01G4/00; H01G4/002; H01G4/005; H01G4/008; H10; H10D; H10D1/00; H10D1/60; H10D1/68; H10D1/692; H10D1/696; H10D1/682; Y; Y10; Y10T; Y10T29/00; Y10T29/43; Y10T29/435
Claims Analysis
Total Claims: 44
Claim 1
Independent Claim
69 words
An integrated circuit capacitor comprising: a first layer comprising a noble metal; a second layer over said first layer, said second layer comprising a conducting oxide; a third layer over said second layer, said third layer comprising a ferroelectric material; a fourth layer over said third layer, said fourth layer comprising a conducting oxide; and a fifth layer over said fourth layer, said fifth layer comprising a noble metal.
Claim 2
Dependent Claim
69 words
An integrated circuit capacitor comprising: a first layer comprising a noble metal; a second layer over said first layer, said second layer comprising a conducting oxide; a third layer over said second layer, said third layer comprising a ferroelectric material; a fourth layer over said third layer, said fourth layer comprising a conducting oxide; and a fifth layer over said fourth layer, said fifth layer comprising a noble metal.
Claim 3
Dependent Claim
23 words
An integrated circuit capacitor according to claim 1 wherein said first and fifth layers have a thickness from about 500Å to about 3000Å.
Claim 4
Dependent Claim
22 words
An integrated circuit capacitor according to claim 1 wherein second and fourth layers have a thickness from about 200Å to about 2000Å.
Claim 5
Dependent Claim
21 words
An integrated circuit capacitor according to claim 1 wherein said third layer has a thickness from about 500Å to about 10,000Å.
Claim 6
Dependent Claim
24 words
An integrated circuit capacitor according to claim 1 wherein said noble metal comprises an element from the group consisting of platinum, palladium, and gold.
Claim 7
Dependent Claim
14 words
An integrated circuit capacitor according to claim 1 wherein said noble metal comprises platinum.
Claim 8
Dependent Claim
15 words
A ferroelectric capacitor according to claim 1 wherein said ferroelectric material is lead zirconate titanate.
Claim 9
Dependent Claim
25 words
An integrated circuit capacitor according to claim 7 wherein said lead zirconate titanate comprises a dopant from the group consisting of lanthanum, tin, and niobium.
Claim 10
Dependent Claim
54 words
The integrated circuit capacitor according to claim 1 wherein said first layer is directly in contact with said second layer, said second layer is directly in contact with said third layer, said third layer is directly in contact with said fourth layer, and said fourth layer is directly in contact with said fifth layer.
Claim 11
Dependent Claim
87 words
A ferroelectric capacitor comprising: a first layer comprising a noble metal; a second layer over said first layer, said second layer comprising a conducting oxide; a third layer over said second layer, said third layer comprising a ferroelectric material; a fourth layer over said third layer, said fourth layer comprising a conducting oxide; and a fifth layer over said fourth layer, said fifth layer comprising a noble metal, wherein said conducting oxide comprises an oxide from the group comprising indium tin oxide, ruthenium oxide, and rhenium oxide.
Claim 12
Dependent Claim
87 words
A ferroelectric capacitor comprising: a first layer comprising a noble metal; a second layer over said first layer, said second layer comprising a conducting oxide; a third layer over said second layer, said third layer comprising a ferroelectric material; a fourth layer over said third layer, said fourth layer comprising a conducting oxide; and a fifth layer over said fourth layer, said fifth layer comprising a noble metal, wherein said conducting oxide comprises an oxide from the group comprising indium tin oxide, ruthenium oxide, and rhenium oxide.
Claim 13
Dependent Claim
53 words
The ferroelectric capacitor according to claim 10 wherein said first layer is directly in contact with said second layer, said second layer is directly in contact with said third layer, said third layer is directly in contact with said fourth layer, and said fourth layer is directly in contact with said fifth layer.
Claim 14
Dependent Claim
77 words
A ferroelectric capacitor comprising: a first layer comprising a noble metal; a second layer over said first layer, said second layer comprising a conducting oxide; a third layer over said second layer, said third layer comprising a ferroelectric material; a fourth layer over said third layer, said fourth layer comprising a conducting oxide; and a fifth layer over said fourth layer, said fifth layer comprising a noble metal, wherein said conducting oxides comprise a conducting pervoskite oxide.
Claim 15
Dependent Claim
77 words
A ferroelectric capacitor comprising: a first layer comprising a noble metal; a second layer over said first layer, said second layer comprising a conducting oxide; a third layer over said second layer, said third layer comprising a ferroelectric material; a fourth layer over said third layer, said fourth layer comprising a conducting oxide; and a fifth layer over said fourth layer, said fifth layer comprising a noble metal, wherein said conducting oxides comprise a conducting pervoskite oxide.
Claim 16
Dependent Claim
53 words
The ferroelectric capacitor according to claim 12 wherein said first layer is directly in contact with said second layer, said second layer is directly in contact with said third layer, said third layer is directly in contact with said fourth layer, and said fourth layer is directly in contact with said fifth layer.
Claim 17
Dependent Claim
96 words
A ferroelectric capacitor comprising: a first layer, comprising a conducting oxide; a second layer over said first layer, said second layer comprising a noble metal; a third layer over said second layer, said third layer comprising a conducting oxide; a fourth layer over said third layer, said fourth layer comprising a ferroelectric material; a fifth layer over said fourth layer, said fifth layer comprising a conducting oxide; a sixth layer over said fifth layer, said sixth layer comprising a noble metal; and a seventh layer over said sixth layer, said seventh layer comprising a conducting oxide.
Claim 18
Dependent Claim
96 words
A ferroelectric capacitor comprising: a first layer, comprising a conducting oxide; a second layer over said first layer, said second layer comprising a noble metal; a third layer over said second layer, said third layer comprising a conducting oxide; a fourth layer over said third layer, said fourth layer comprising a ferroelectric material; a fifth layer over said fourth layer, said fifth layer comprising a conducting oxide; a sixth layer over said fifth layer, said sixth layer comprising a noble metal; and a seventh layer over said sixth layer, said seventh layer comprising a conducting oxide.
Claim 19
Dependent Claim
18 words
A ferroelectric capacitor according to claim 14 wherein said first layer is grown on a SiO 2 layer.
Claim 20
Dependent Claim
24 words
A ferroelectric capacitor according to claim 14 wherein said first, third, fifth, and seventh layers have a thickness from about 200Å to about 2000Å.
Claim 21
Dependent Claim
22 words
A ferroelectric capacitor according to claim 14 wherein said second and sixth layers have a thickness from about 500Å to about 3000Å.
Claim 22
Dependent Claim
20 words
A ferroelectric capacitor according to claim 14 wherein said fourth layer has a thickness from about 500Å to about 10,000Å.
Claim 23
Dependent Claim
23 words
A ferroelectric capacitor according to claim 14 wherein said noble metal comprises an element from the group consisting of platinum, palladium, and gold.
Claim 24
Dependent Claim
13 words
A ferroelectric capacitor according to claim 14 wherein said noble metal comprises platinum.
Claim 25
Dependent Claim
15 words
A ferroelectric capacitor according to claim 14 wherein said ferroelectric material is lead zironcate titanate.
Claim 26
Dependent Claim
24 words
A ferroelectric capacitor according to claim 21 wherein said lead zirconate titanate comprises a dopant from the group consisting of lanthanum, tin, and niobium.
Claim 27
Dependent Claim
27 words
A ferroelectric capacitor according to claim 14 wherein said conducting oxide comprises an oxide from the group consisting of indium tin oxide, ruthenium oxide, and rhenium oxide.
Claim 28
Dependent Claim
16 words
A ferroelectric capacitor according to claim 14 wherein said conducting oxide comprises a conducting perovskite oxide.
Claim 29
Dependent Claim
16 words
The ferroelectric capacitor according to claim 14 wherein said layers are in contact with each other.
Claim 30
Dependent Claim
75 words
The ferroelectric capacitor according to claim 14 wherein said first layer is directly in contact with said second layer, said second layer is directly in contact with said third layer, said third layer is directly in contact with said fourth layer, said fourth layer is directly in contact with said fifth layer, said fifth layer is directly in contact with said sixth layer, and said sixth layer is directly in contact with said seventh layer.
Claim 31
Independent Claim
91 words
A method for forming a ferroelectric capacitor comprising the steps of: establishing a first layer, said first layer comprising a noble metal; annealing said noble metal; establishing a second layer, comprising a conducting oxide, over said first layer; annealing said conducting oxide; establishing a third layer, comprising a ferroelectric material, over said second layer; annealing said third layer; establishing a fourth layer, comprising a conducting oxide, over said third layer; annealing said conducting oxide; establishing a fifth layer, comprising a noble metal, over said fourth layer; and annealing said noble metal.
Claim 32
Independent Claim
91 words
A method for forming a ferroelectric capacitor comprising the steps of: establishing a first layer, said first layer comprising a noble metal; annealing said noble metal; establishing a second layer, comprising a conducting oxide, over said first layer; annealing said conducting oxide; establishing a third layer, comprising a ferroelectric material, over said second layer; annealing said third layer; establishing a fourth layer, comprising a conducting oxide, over said third layer; annealing said conducting oxide; establishing a fifth layer, comprising a noble metal, over said fourth layer; and annealing said noble metal.
Claim 33
Dependent Claim
12 words
The method of claim 27 wherein said layers are established by deposition.
Claim 34
Dependent Claim
12 words
The method of claim 28 wherein said layers are deposited in situ.
Claim 35
Dependent Claim
14 words
The method of claim 28 wherein said layers are deposited by ion cluster beam.
Claim 36
Dependent Claim
51 words
The method of claim 28 wherein said layers are deposited with an acceleration potential in the range of about 0 to about 6.0 kV, an ionization current in the range of about 0 to about 200 mA and a substrate heat in the range of about 25 to about 900° C.
Claim 37
Dependent Claim
52 words
The method according to claim 27 wherein said first layer is directly in contact with said second layer, said second layer is directly in contact with said third layer, said third layer is directly in contact with said fourth layer, and said fourth layer is directly in contact with said fifth layer.
Claim 38
Independent Claim
120 words
A method for forming a ferroelectric capacitor comprising the steps of: establishing a first layer, comprising a conducting oxide; annealing said conducting oxide; establishing a second layer, comprising a noble metal, over said first layer; annealing said noble metal; establishing a third layer, comprising a conducting oxide, over said second layer; annealing said third layer; establishing a fourth layer, comprising a ferroelectric material, over said third layer; annealing said ferroelectric material; establishing a fifth layer, comprising a conducting oxide, over said fourth layer; annealing said conducting oxide; establishing a sixth layer, comprising a noble metal, over said fifth layer; annealing said sixth layer; establishing a seventh layer, comprising a conducting oxide, over said sixth layer; and annealing said conducting oxide.
Claim 39
Independent Claim
120 words
A method for forming a ferroelectric capacitor comprising the steps of: establishing a first layer, comprising a conducting oxide; annealing said conducting oxide; establishing a second layer, comprising a noble metal, over said first layer; annealing said noble metal; establishing a third layer, comprising a conducting oxide, over said second layer; annealing said third layer; establishing a fourth layer, comprising a ferroelectric material, over said third layer; annealing said ferroelectric material; establishing a fifth layer, comprising a conducting oxide, over said fourth layer; annealing said conducting oxide; establishing a sixth layer, comprising a noble metal, over said fifth layer; annealing said sixth layer; establishing a seventh layer, comprising a conducting oxide, over said sixth layer; and annealing said conducting oxide.
Claim 40
Dependent Claim
12 words
The method of claim 33 wherein said layers are established by deposition.
Claim 41
Dependent Claim
12 words
The method of claim 34 wherein said layers are deposited in situ.
Claim 42
Dependent Claim
14 words
The method of claim 34 wherein said layers are deposited by ion cluster beam.
Claim 43
Dependent Claim
51 words
The method of claim 34 wherein said layers are deposited with an acceleration potential in the range of about 0 to about 6.0 kV, an ionization current in the range of about 0 to about 200 mA and a substrate heat in the range of about 25 to about 900° C.
Claim 44
Dependent Claim
74 words
The method according to claim 33 wherein said first layer is directly in contact with said second layer, said second layer is directly in contact with said third layer, said third layer is directly in contact with said fourth layer, said fourth layer is directly in contact with said fifth layer, said fifth layer is directly in contact with said sixth layer, and said sixth layer is directly in contact with said seventh layer.
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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) | 1995-08-25 | 1996-02-24 | 1996-08-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-08-25 | 2000-02-24 | 2000-08-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-08-25 | 2004-02-24 | 2004-08-25 | $7700.00 | Window Closed / Lapsed |