Patent US5155573A successfully refreshed from Google Patents.
US5155573A
Expired / Lapsed
US
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Ferroelectric capacitor and a semiconductor device having the same
Assignee: Toshiba Corp
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Filing: 1990-12-24
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Granted: 1992-10-13
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Expires: 2010-12-24
Abstract
Abstract A ferroelectric capacitor includes a ferroelectric layer consisting of lead zirconate titanate formed on a silicon substrate, a plurality of rectangular trenches formed in the direction of thickness of the ferroelectric layer with a ferroelectric material therebetween, and first and second electrodes consisting of metal tungsten buried in the trenches to oppose each other with the ferroelectric material therebetween.
Inventors
- 👤 Kazuhide Abe
- 👤 Hiroshi Toyoda
- 👤 Koji Yamakawa
- 👤 Motomasa Imai
- 👤 Mitsuo Harata
- 👤 Koji Sakui
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 14:07
CPC Classifications
H; H10; H10B; H10B53/00; H10B53/30; H10D; H10D1/00; H10D1/60; H10D1/68; H10D1/692
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
48 words
A ferroelectric capacitor comprising: a ferroelectric layer formed on a substrate; a plurality of trenches formed in the direction of thickness of said ferroelectric layer to oppose each other with a ferroelectric material therebetween; and first and second electrodes buried in said trenches with said ferroelectric material therebetween.
Claim 2
Dependent Claim
48 words
A ferroelectric capacitor comprising: a ferroelectric layer formed on a substrate; a plurality of trenches formed in the direction of thickness of said ferroelectric layer to oppose each other with a ferroelectric material therebetween; and first and second electrodes buried in said trenches with said ferroelectric material therebetween.
Claim 3
Dependent Claim
36 words
A capacitor according to claim 1, wherein said first and second electrodes are buried in said trenches with an insulating material therebetween at a portion except for a contact portion with respect to said ferroelectric material.
Claim 4
Dependent Claim
15 words
A capacitor according to claim 1, wherein said ferroelectric layer consists of lead zirconate titanate.
Claim 5
Dependent Claim
19 words
A capacitor according to claim 1, wherein an insulating film is interposed between said substrate and said ferroelectric layer.
Claim 6
Dependent Claim
13 words
A capacitor according to claim 4, wherein said insulating film consists of magnesia.
Claim 7
Dependent Claim
84 words
A semiconductor device comprising: a substrate; an insulating film formed on said substrate; a ferroelectric capacitor constituted by a ferroelectric layer formed on said insulating film, a plurality of trenches formed in the direction of thickness of said ferroelectric layer with a ferroelectric material therebetween, and first and second electrodes buried in said trenches to oppose each other with said ferroelectric material therebetween; and a transistor formed on said substrate and connected to one of said first and second electrodes of said ferroelectric capacitor.
Claim 8
Dependent Claim
84 words
A semiconductor device comprising: a substrate; an insulating film formed on said substrate; a ferroelectric capacitor constituted by a ferroelectric layer formed on said insulating film, a plurality of trenches formed in the direction of thickness of said ferroelectric layer with a ferroelectric material therebetween, and first and second electrodes buried in said trenches to oppose each other with said ferroelectric material therebetween; and a transistor formed on said substrate and connected to one of said first and second electrodes of said ferroelectric capacitor.
Claim 9
Dependent Claim
13 words
A device according to claim 6, wherein said insulating film consists of magnesia.
Claim 10
Dependent Claim
55 words
A device according to claim 6, wherein said substrate consists of silicon, and said transistor is constituted by source and drain regions formed on said substrate, a gate insulating film formed on said substrate including a channel region formed between said source and drain regions, and a gate electrode formed on said gate insulating film.
Claim 11
Dependent Claim
33 words
A device according to claim 6 or 8, wherein one of said first and second electrodes of said ferroelectric capacitor is directly connected to a source region or drain region of said transistor.
Claim 12
Dependent Claim
27 words
A device according to claim 6, wherein the other one of said first and second electrodes is connected to a wiring layer formed on said ferroelectric layer.
Claim 13
Dependent Claim
20 words
A device according to claim 10, wherein an insulating film is interposed between said ferroelectric layer and said wiring layer.
Claim 14
Dependent Claim
102 words
A semiconductor device comprising: a substrate; an insulating film formed on said substrate; a ferroelectric capacitor constituted by a ferroelectric layer formed on said insulating film, a plurality of trenches formed in the direction of thickness of said ferroelectric layer with a ferroelectric material therebetween, and first and second electrodes alternately buried in said trenches to oppose each other with said ferroelectric material therebetween; a transistor formed on said substrate and connected to said first electrode of said ferroelectric capacitor; and a wiring layer, formed on said ferroelectric layer of said ferroelectric capacitor, for commonly connecting said second electrode of said capacitor.
Claim 15
Dependent Claim
102 words
A semiconductor device comprising: a substrate; an insulating film formed on said substrate; a ferroelectric capacitor constituted by a ferroelectric layer formed on said insulating film, a plurality of trenches formed in the direction of thickness of said ferroelectric layer with a ferroelectric material therebetween, and first and second electrodes alternately buried in said trenches to oppose each other with said ferroelectric material therebetween; a transistor formed on said substrate and connected to said first electrode of said ferroelectric capacitor; and a wiring layer, formed on said ferroelectric layer of said ferroelectric capacitor, for commonly connecting said second electrode of said capacitor.
Claim 16
Dependent Claim
13 words
A device according to claim 12, wherein said insulating film consists of magnesia.
Claim 17
Dependent Claim
55 words
A device according to claim 12, wherein said substrate consists of silicon, and said transistor is constituted by source and drain regions formed on said substrate, a gate insulating film formed on said substrate including a channel region formed between said source and drain regions, and a gate electrode formed on said gate insulating film.
Claim 18
Dependent Claim
28 words
A device according to claim 14, wherein said first electrode of said ferroelectric capacitor is directly connected to one of said source and drain regions of said transistor.
Claim 19
Dependent Claim
20 words
A device according to claim 12, wherein an insulating film is interposed between said ferroelectric layer and said wiring layer.
Claim 20
Dependent Claim
36 words
A device according to claim 12, wherein said transistor has source and drain regions and said first electrode of said ferroelectric capacitor is directly connected to one of said source and drain regions of said transistor.
References Cited (Backward Citations)
US3569795A
Cited
DE2042611A1
Cited
US4707897A
Cited
US5021843A
Cited
US4967247A
Cited
EP0380326A2
Cited
US5031144A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1995-10-13 | 1996-04-13 | 1996-10-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-10-13 | 2000-04-13 | 2000-10-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-10-13 | 2004-04-13 | 2004-10-13 | $7700.00 | Window Closed / Lapsed |