US5930106A
Expired / Lapsed
US
⏱️ 0.0 years remaining
DRAM capacitors made from silicon-germanium and electrode-limited conduction dielectric films
Assignee: Round Rock Research LLC
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Filing: 1996-07-11
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Granted: 1999-07-27
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Expires: 2016-07-11
Abstract
Abstract An exemplary implementation of the present invention includes a capacitor for a dynamic random access memory cell having a first plate; a second plate; and a dielectric layer interposed between said first and second plates, with the dielectric layer being dominated by electrode-limited conduction, which includes tantalum pentoxide and silicon nitride, or a combination of the two. In a preferred implementation, one of the two capacitor plates is formed from a silicon-germanium layer, the second plate is formed from a metal and the dielectric layer is formed from tantalum pentoxide.
Inventors
- 👤 Scott J. Deboer
- 👤 Klaus F. Schuegraf
- 👤 Ronald A. Weimer
- 👤 Randhir P. S. Thakur
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 06:27
CPC Classifications
H; H10; H10D; H10D1/00; H10D1/60; H10D1/68; H10B; H10B12/00; H10B12/01; H10B12/02; H10B12/03; H10B12/033
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
51 words
A capacitor for a dynamic random access memory cell comprising: a first plate; a second plate; and a dielectric layer interposed between said first and second plates, said dielectric layer being dominated by electrode-limited conduction; wherein at least one of said plates comprises a silicon-germanium layer as its charge storing surface.
Claim 2
Dependent Claim
51 words
A capacitor for a dynamic random access memory cell comprising: a first plate; a second plate; and a dielectric layer interposed between said first and second plates, said dielectric layer being dominated by electrode-limited conduction; wherein at least one of said plates comprises a silicon-germanium layer as its charge storing surface.
Claim 3
Dependent Claim
19 words
The capacitor of claim 1, wherein said germanium-silicon layer comprises 10 14 cm -3 to less than 100% germanium.
Claim 4
Dependent Claim
21 words
The capacitor of claim 2, wherein said silicon-germanium layer has a rough surface morphology characterized by macroscopic islanding of alloy crystals.
Claim 5
Dependent Claim
31 words
The capacitor of claim 1, wherein only one of said plates comprise a silicon-germanium layer as its charge storing surface and the remaining plate comprises metal as its charge storing surface.
Claim 6
Dependent Claim
32 words
The capacitor of claim 4, wherein said metal is a metal selected from the group consisting of titanium, titanium silicide, titanium nitride, tungsten, tungsten silicide, tungsten nitride, molybdenum and other refractory metals.
Claim 7
Dependent Claim
22 words
The capacitor of claim 1, wherein said dielectric layer comprises a tantalum pentoxide film having a thickness no greater than 120 Å.
Claim 8
Dependent Claim
22 words
The capacitor of claim 1, wherein said dielectric layer comprises a tantalum pentoxide film having a thickness no greater than 85 Å.
Claim 9
Dependent Claim
22 words
The capacitor of claim 1, wherein said dielectric layer comprises a silicon nitride film having a thickness no greater than 100 Å.
Claim 10
Dependent Claim
28 words
The capacitor of claim 1, wherein said dielectric layer comprises a combination of tantalum pentoxide and silicon nitride films having a combined thickness no greater than 150 Å.
Claim 11
Dependent Claim
22 words
The capacitor of claim 1, wherein said dielectric layer comprises a silicon nitride film having a thickness no greater than 60 Å.
Claim 12
Dependent Claim
23 words
The capacitor of claim 1, wherein said dielectric layer comprises a barium strontium titanate film having a thickness no greater than 1000 Å.
Claim 13
Dependent Claim
43 words
A capacitor in dynamic random access memory cell comprising: a first plate having a silicon-germanium layer as its charge storing surface; a second plate; and a dielectric layer interposed between said first and second plates, said dielectric layer being dominated by electrode-limited conduction.
Claim 14
Dependent Claim
43 words
A capacitor in dynamic random access memory cell comprising: a first plate having a silicon-germanium layer as its charge storing surface; a second plate; and a dielectric layer interposed between said first and second plates, said dielectric layer being dominated by electrode-limited conduction.
Claim 15
Dependent Claim
19 words
The capacitor of claim 12, wherein said germanium-silicon layer comprises 10 14 cm -3 to less than 100% germanium.
Claim 16
Dependent Claim
21 words
The capacitor of claim 12, wherein said silicon-germanium layer has a rough surface morphology characterized by macroscopic islanding of alloy crystals.
Claim 17
Dependent Claim
17 words
The capacitor of claim 12, wherein said second plate comprises a metal as its charge storing surface.
Claim 18
Dependent Claim
32 words
The capacitor of claim 15, wherein said metal is a metal selected from the group consisting of titanium, titanium silicide, titanium nitride, tungsten, tungsten silicide, tungsten nitride, molybdenum and other refractory metals.
Claim 19
Dependent Claim
22 words
The capacitor of claim 16, wherein said dielectric layer comprises a tantalum pentoxide film having a thickness no greater than 120 Å.
Claim 20
Dependent Claim
22 words
The capacitor of claim 15, wherein said dielectric layer comprises a tantalum pentoxide film having a thickness no greater than 85 Å.
Claim 21
Dependent Claim
22 words
The capacitor of claim 15, wherein said dielectric layer comprises a silicon nitride film having a thickness no greater than 100 Å.
Claim 22
Dependent Claim
28 words
The capacitor of claim 15, wherein said dielectric layer comprises a combination of tantalum pentoxide and silicon nitride films having a combined thickness no greater than 150 Å.
Claim 23
Dependent Claim
22 words
The capacitor of claim 15, wherein said dielectric layer comprises a silicon nitride film having a thickness no greater than 60 Å.
Claim 24
Dependent Claim
23 words
The capacitor of claim 15, wherein said dielectric layer comprises a barium strontium titanate film having a thickness no greater than 1000 Å.
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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) | 2002-07-26 | 2003-01-25 | 2003-07-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-07-26 | 2007-01-25 | 2007-07-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-07-26 | 2011-01-25 | 2011-07-27 | $7700.00 | Window Closed / Lapsed |