US6027947A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Partially or completely encapsulated top electrode of a ferroelectric capacitor
Assignee: Monterey Research LLC
•
Filing: 1997-03-27
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Granted: 2000-02-22
•
Expires: 2017-03-27
Abstract
Abstract A ferroelectric capacitor includes a bottom electrode, a top electrode, and a ferroelectric layer located between the top and bottom electrodes that extends to completely encapsulate the top electrode, except for a contact hole to allow metalization of the top electrode. The total encapsulation of the top electrode reduces the sensitivity of the ferroelectric capacitor to hydrogen and thus improves electrical switching performance. The encapsulation technique can also be used to improve the performance of ferroelectric transistors and other devices.
Inventors
- 👤 Thomas A. Evans
- 👤 George Argos, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 18:04
CPC Classifications
H; H10; H10B; H10B53/00; H10B53/30; H10D; H10D1/00; H10D1/60; H10D1/68; H10D1/682; H10D30/00; H10D30/01; H10D30/021; H10D30/0411; H10D30/60; H10D30/701; H10D64/00; H10D64/01; H10D64/031; H10D64/035
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
56 words
A fabrication method comprising the steps of: forming a ferroelectric FET including at least two source/drain regions and a ferroelectric gate structure including a ferroelectric dielectric and a polysilicon gate directly on a silicon substrate including the source/drain regions; and encapsulating the ferroelectric gate structure with a hydrogen-barrier cap layer distinct from the ferroelectric gate structure.
Claim 2
Dependent Claim
56 words
A fabrication method comprising the steps of: forming a ferroelectric FET including at least two source/drain regions and a ferroelectric gate structure including a ferroelectric dielectric and a polysilicon gate directly on a silicon substrate including the source/drain regions; and encapsulating the ferroelectric gate structure with a hydrogen-barrier cap layer distinct from the ferroelectric gate structure.
Claim 3
Dependent Claim
48 words
The fabrication method of claim 1 in which the step of encapsulating the ferroelectric gate structure comprises the step of encapsulating the ferroelectric gate structure with a layer of material selected from a group consisting of doped and undoped nitrides, titanates, zirconates, niobates, tantalates, stanates, hafnates, and manganates.
Claim 4
Dependent Claim
29 words
The fabrication method of claim 1 in which the step of encapsulating the ferroelectric gate structure comprises the step of encapsulating the ferroelectric gate structure with a ferroelectric layer.
Claim 5
Dependent Claim
43 words
The fabrication method of claim 1 in which the step of encapsulating the ferroelectric gate structure comprises the step of encapsulating the ferroelectric gate structure with a layer of material selected from a group consisting of doped and undoped PZT, BST, and SBT.
Claim 6
Dependent Claim
46 words
The fabrication method of claim 1 in which the step of encapsulating the ferroelectric gate structure with a cap layer comprises the steps of: forming the cap layer over the entire ferroelectric FET, including the source/drain regions; and etching the cap layer over the source/drain regions.
Claim 7
Dependent Claim
46 words
The fabrication method of claim 1 further comprising the steps of: forming an oxide layer over the ferroelectric FET; forming vias through the oxide layer to the source/drain regions; and forming a via through the oxide layer and the cap layer to the ferroelectric gate structure.
Claim 8
Dependent Claim
20 words
The fabrication method of claim 6 further comprising the step of metalizing the source/drain regions and the ferroelectric gate structure.
Claim 9
Dependent Claim
15 words
The fabrication method of claim 6 further comprising the step of planarizing the oxide 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) | 2003-02-21 | 2003-08-23 | 2004-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-02-21 | 2007-08-23 | 2008-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-02-21 | 2011-08-23 | 2012-02-22 | $7700.00 | Window Closed / Lapsed |