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US6004825A
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Method for making three dimensional ferroelectric memory
Assignee: Round Rock Research LLC
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Filing: 1998-02-23
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Granted: 1999-12-21
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Expires: 2018-02-23
Abstract
Abstract A three dimensional ferroelectric memory device formed on a semiconductor substrate has insulative material formed between rows of conductors to reduce cross talk between the conductors. Access circuitry or other circuitry is formed beneath the three dimensional structure. Continuous conductors, or staggered vias provide for connection to conductors forming the memory cells. An access circuit is provided which eliminates the need for an access transistor for each memory cell by using a memory cell with a reference cell in combination with sensing circuitry. Read cycles are followed by write cycles and an equilibrate cycle to reverse the effects of destructive reads on the memory cells. Side by side memory structures provide the ability to access using either a folded or open bit line circuit.
Inventors
- 👤 Mirmajid Seyyedy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 02:26
CPC Classifications
H; H10; H10B; H10B53/00; G; G11; G11C; G11C11/00; G11C11/21; G11C11/22
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
112 words
A method of constructing a three dimensional ferroelectric memory device on a semiconductor substrate comprising the steps of: forming a first layer of bottom conductors on the substrate; forming a first bottom insulative layer between the conductors of said first layer of bottom conductors; polishing the first layer of bottom conductors and the first bottom insulative layer; forming a first ferroelectric layer formed on top of the polished layer; forming a first layer of top conductors on top of the first ferroelectric layer to form a first layer of ferroelectric memory cells where the conductors of the first layer of top conductors overlap the conductors of the first layer of bottom conductors.
Claim 2
Independent Claim
112 words
A method of constructing a three dimensional ferroelectric memory device on a semiconductor substrate comprising the steps of: forming a first layer of bottom conductors on the substrate; forming a first bottom insulative layer between the conductors of said first layer of bottom conductors; polishing the first layer of bottom conductors and the first bottom insulative layer; forming a first ferroelectric layer formed on top of the polished layer; forming a first layer of top conductors on top of the first ferroelectric layer to form a first layer of ferroelectric memory cells where the conductors of the first layer of top conductors overlap the conductors of the first layer of bottom conductors.
Claim 3
Dependent Claim
46 words
The method of constructing a three dimensional ferroelectric memory device of claim 1 and further comprising: forming a first top insulative layer between the conductors of said first layer of top conductors; and polishing the first layer of top conductors and the first top insulative layer.
Claim 4
Dependent Claim
81 words
The method of constructing a three dimensional ferroelectric memory device of claim 2 and further comprising: forming a second ferroelectric layer on top of the polished first layer of top conductors and the first top insulative layer; and forming a second layer of top conductors on top of the second ferroelectric layer to form a second layer of ferroelectric memory cells where the conductors of the second layer of top conductors overlap the conductors of the first layer of top conductors.
Claim 5
Dependent Claim
126 words
The method of constructing a three dimensional ferroelectric memory device of claim 1 and further comprising: forming an isolating layer on top of the first layer of top conductors; forming a second layer of bottom conductors on the isolating layer; forming a second bottom insulative layer between the conductors of said second layer of bottom conductors; polishing the second layer of bottom conductors and the second bottom insulative layer; forming a second ferroelectric layer formed on top of the polished second layer; and forming a second layer of top conductors on top of the second ferroelectric layer to form a second layer of ferroelectric memory cells where the conductors of the second layer of top conductors overlap the conductors of the second layer of bottom conductors.
Claim 6
Dependent Claim
39 words
The method of constructing a three dimensional ferroelectric memory device of claim 4 and further comprising forming successive layers of ferroelectric memory cells by duplicating selected steps of claim 4 to form a multi layer three dimensional ferroelectric memory.
Claim 7
Independent Claim
75 words
A method of constructing a three dimensional ferroelectric memory device on a semiconductor substrate comprising the steps of: forming circuitry in the substrate; forming a first isolating layer on top of the circuitry; forming a first layer of bottom conductors on top of the first isolating layer; forming a first ferroelectric layer on top of said first layer of bottom conductors; and forming a first layer of top conductors on top of the ferroelectric layer.
Claim 8
Independent Claim
75 words
A method of constructing a three dimensional ferroelectric memory device on a semiconductor substrate comprising the steps of: forming circuitry in the substrate; forming a first isolating layer on top of the circuitry; forming a first layer of bottom conductors on top of the first isolating layer; forming a first ferroelectric layer on top of said first layer of bottom conductors; and forming a first layer of top conductors on top of the ferroelectric 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) | 2002-12-20 | 2003-06-21 | 2003-12-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-12-20 | 2007-06-21 | 2007-12-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-12-20 | 2011-06-21 | 2011-12-21 | $7700.00 | Window Closed / Lapsed |