US5338951A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Structure of high dielectric constant metal/dielectric/semiconductor capacitor for use as the storage capacitor in memory devices
Assignee: Ramtron International Corp
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Filing: 1991-11-06
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Granted: 1994-08-16
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Expires: 2011-11-06
Abstract
Abstract A capacitor for a semiconductor structure is formed having a substrate, a stack of a buffer layer and a layer of ferroelectric material, and a top electrode. The capacitor can also have a layer of polysilicon between the substrate and the buffer layer. A method for forming the same, through establishing a substrate, a buffer layer and a layer of ferroelectric material, defining and annealing the buffer layer and layer of ferroelectric material, and establishing a top electrode, is also disclosed.
Inventors
- 👤 George Argos, Jr.
- 👤 Thottam S. Kalkur
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 03:07
CPC Classifications
H; H10; H10B; H10B53/00; H10D; H10D1/00; H10D1/60; H10D1/62; H10D1/66
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
65 words
A semiconductor capacitor structure comprising: a substrate; a buffer layer located directly over and in contact with said substrate, wherein said buffer layer is comprised of a compound selected from the group comprised of zirconium oxide, lanthanum oxide and titanium oxide; a layer of ferroelectric material located directly over and in contact with said buffer layer; and a top electrode located over said ferroelectric material.
Claim 2
Dependent Claim
65 words
A semiconductor capacitor structure comprising: a substrate; a buffer layer located directly over and in contact with said substrate, wherein said buffer layer is comprised of a compound selected from the group comprised of zirconium oxide, lanthanum oxide and titanium oxide; a layer of ferroelectric material located directly over and in contact with said buffer layer; and a top electrode located over said ferroelectric material.
Claim 3
Dependent Claim
26 words
The capacitor of claim 1 wherein said ferroelectric material is Pb(Zr x Ti 1-x )O 3 wherein x is in the range of 0 to 1.0.
Claim 4
Dependent Claim
19 words
The capacitor of claim 1 wherein said buffer layer is comprised of a material having a high dielectric constant.
Claim 5
Dependent Claim
13 words
The capacitor of claim 1 wherein said top electrode is a noble metal.
Claim 6
Dependent Claim
20 words
The capacitor of claim 4 wherein said noble metal is an element selected from the group comprising platinum and palladium.
Claim 7
Dependent Claim
22 words
The capacitor of claim 4 wherein said noble metal is an alloy selected from group comprising platinum, palladium, titanium, bismuth, and rhenium.
Claim 8
Dependent Claim
13 words
The capacitor of claim 1 wherein said top electrode is comprised of polysilicon.
Claim 9
Dependent Claim
16 words
The capacitor of claim 1 wherein said substrate is comprised of substantially undoped single crystal silicon.
Claim 10
Dependent Claim
20 words
The capacitor of claim 1 wherein said substrate is comprised of a doped (acceptor or donor) single crystal silicon layer.
Claim 11
Dependent Claim
18 words
The capacitor of claim 1 wherein said substrate is comprised of a polysilicon layer on a silicon substrate.
Claim 12
Dependent Claim
16 words
The capacitor of claim 1 wherein said buffer layer has a thickness of substantially 300 Å.
Claim 13
Dependent Claim
18 words
The capacitor of claim 1 wherein said layer of ferroelectric material has a thickness of substantially 3000 Å.
Claim 14
Dependent Claim
60 words
A semiconductor capacitor structure comprising: a substrate; a layer of polysilicon located directly over and in contact with said substrate; a buffer layer located directly over and in contact with said layer of polysilicon; a layer of ferroelectric material located directly over and in contact with said buffer layer; and a top electrode located over said layer of ferroelectric material.
Claim 15
Dependent Claim
60 words
A semiconductor capacitor structure comprising: a substrate; a layer of polysilicon located directly over and in contact with said substrate; a buffer layer located directly over and in contact with said layer of polysilicon; a layer of ferroelectric material located directly over and in contact with said buffer layer; and a top electrode located over said layer of ferroelectric material.
Claim 16
Dependent Claim
14 words
The capacitor of claim 1 wherein said semiconductor capacitor structure has no bottom electrode.
Claim 17
Dependent Claim
13 words
The capacitor of claim 1 wherein said substrate serves as a bottom electrode.
Claim 18
Dependent Claim
14 words
The capacitor of claim 13 wherein said semiconductor capacitor structure has no bottom electrode.
Claim 19
Dependent Claim
13 words
The capacitor of claim 13 wherein said substrate serves as a bottom electrode.
Claim 20
Dependent Claim
86 words
A semiconductor capacitor structure consisting essentially of: a substrate; a buffer layer located directly over and in contact with said substrate, wherein said buffer layer comprises a compound selected from the group comprised of zirconium oxide, lanthanum oxide and titanium oxide; a layer of ferroelectric material located directly over and in contact with said buffer layer, the ferroelectric material being Pb(Zr x Ti 1-x ) O 3 where x is in the range of 0 to 1.0; and a top electrode located over said ferroelectric material.
Claim 21
Dependent Claim
86 words
A semiconductor capacitor structure consisting essentially of: a substrate; a buffer layer located directly over and in contact with said substrate, wherein said buffer layer comprises a compound selected from the group comprised of zirconium oxide, lanthanum oxide and titanium oxide; a layer of ferroelectric material located directly over and in contact with said buffer layer, the ferroelectric material being Pb(Zr x Ti 1-x ) O 3 where x is in the range of 0 to 1.0; and a top electrode located over said ferroelectric material.
Claim 22
Dependent Claim
57 words
A semiconductor capacitor structure consisting essentially of: a substrate; a buffer layer located directly over and in contact with said substrate; a layer of polysilicon located between said substrate and said buffer layer; a layer of ferroelectric material located directly over and in contact with said buffer layer; and a top electrode located over said ferroelectric material.
Claim 23
Dependent Claim
57 words
A semiconductor capacitor structure consisting essentially of: a substrate; a buffer layer located directly over and in contact with said substrate; a layer of polysilicon located between said substrate and said buffer layer; a layer of ferroelectric material located directly over and in contact with said buffer layer; and a top electrode located over said ferroelectric material.
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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) | 1997-08-15 | 1998-02-14 | 1998-08-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-08-15 | 2002-02-14 | 2002-08-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-08-15 | 2006-02-14 | 2006-08-16 | $7700.00 | Window Closed / Lapsed |