Patent US1905557A successfully refreshed from Google Patents.
Patent US5850089A successfully refreshed from Google Patents.
US5850089A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Modulated-structure of PZT/PT ferroelectric thin films for non-volatile random access memories
Assignee: AMERICAN RESEARCH Corp OF VIRGINIA A CORP OF
•
Filing: 1992-03-13
•
Granted: 1998-12-15
•
Expires: 2012-03-13
Abstract
Abstract Modulated-structure polycrystalline or heteroepitaxial multilayers of PZT/PT ferroelectric thin films are deposited on a substrate, preferably by laser ablation. The laser ablation of the PZT/PT layers onto a prepared substrate occurs while maintaining the substrate at a temperature between 380 DEG C. to about 650 DEG C. The target source for the PZT/PT laser ablated film may be either bulk PZT and PT ceramics or powders or individual metal oxides or metal pellets. The ferroelectric thin film device may be used for a random access memory.
Inventors
- 👤 Usha Varshney
- 👤 Angus Ian Kingon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 06:03
CPC Classifications
H; H10; H10B; H10B53/00; C; C23; C23C; C23C14/00; C23C14/06; C23C14/08; C23C14/22; C23C14/24; C23C14/28; H10D; H10D1/00; H10D1/60; H10D1/68; H10D1/682; H10D1/684
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
25 words
A ferroelectric thin film structure comprising a substrate and a modulated lead zirconate titanate and PbTiO 3 heterostructure ferroelectric thin film formed on said substrate.
Claim 2
Dependent Claim
25 words
A ferroelectric thin film structure comprising a substrate and a modulated lead zirconate titanate and PbTiO 3 heterostructure ferroelectric thin film formed on said substrate.
Claim 3
Dependent Claim
14 words
The structure of claim 1, wherein said modulated structure is deposited onto said substrate.
Claim 4
Dependent Claim
22 words
The structure of claim 1, wherein said substrate is formed of a material selected from the group consisting of Si and GaAs.
Claim 5
Dependent Claim
34 words
The structure of claim 1, wherein said structure is fabricated by a method comprising the steps of: preparing said substrate for film deposition; and depositing said modulated heterostructure ferroelectric thin film onto said substrate.
Claim 6
Dependent Claim
23 words
The structure of claim 4, wherein said substrate is formed of a semiconductor material selected from the group consisting of Si and GaAs.
Claim 7
Dependent Claim
44 words
The structure of claim 4, wherein said thin film deposition step includes the step of directing laser energy onto a target, said target including a pellet formed of PbO, a pellet formed of ZrO 2 , and a pellet formed of TiO 2 .
Claim 8
Dependent Claim
48 words
The structure of claim 4, wherein said thin film deposition step includes the step of directing laser energy onto a target, said target including a pellet formed of Pb, a pellet formed of Zr, and a pellet formed of Ti, and wherein said method includes a post-oxidation step.
Claim 9
Dependent Claim
38 words
The structure of claim 4, wherein said thin film deposition step includes the step of directing laser energy onto a target, said target including bulk lead zirconate titanate powder or ceramic and bulk PbTiO 3 powder or ceramic.
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) | 2001-12-14 | 2002-06-15 | 2002-12-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-12-14 | 2006-06-15 | 2006-12-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-12-14 | 2010-06-15 | 2010-12-15 | $7700.00 | Window Closed / Lapsed |