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Patent US5686341A successfully refreshed from Google Patents.
US5686341A
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Method of fabricating an electrically alterable resistive component using germanium
Assignee: Unisys Corp
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Filing: 1995-11-27
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Granted: 1997-11-11
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Expires: 2015-11-27
Abstract
Abstract A memory cell includes a pair of spaced apart conductors on an insulating layer, and a novel electrically alterable resistive component between the conductors. This resistive component consist essentially of Germanium, having a crystalline grain size which is smaller than polycrystalline; and the Germanium switches from a high resistance to a low resistance upon the application of a threshold voltage across the conductors.
Inventors
- 👤 Bruce Boyd Roesner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 08:21
CPC Classifications
H; H10; H10B; H10B20/00
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
142 words
A process for fabricating an electrically alterable resistive component in an integrated circuit which includes a semiconductor substrate having a major surface and an insulating layer over said surface; said process including the steps of: forming a bottom electrical lead on said insulating layer; depositing and patterning a layer of electrically alterable material, which changes resistance irreversibly, such that the patterned electrically alterable material overlies and is coupled to said bottom lead; forming a top electrical lead which extends over and is there coupled to said electrically alterable material; limiting said electrically alterable material to consist of germanium, with or without dopant atoms; and, confining said electrically alterable material, from its deposition through a predetermined final step that completes said integrated circuit, to temperatures which cause said electrically alterable material to have a smaller crystalline grain size than that of polycrystalline germanium.
Claim 2
Dependent Claim
142 words
A process for fabricating an electrically alterable resistive component in an integrated circuit which includes a semiconductor substrate having a major surface and an insulating layer over said surface; said process including the steps of: forming a bottom electrical lead on said insulating layer; depositing and patterning a layer of electrically alterable material, which changes resistance irreversibly, such that the patterned electrically alterable material overlies and is coupled to said bottom lead; forming a top electrical lead which extends over and is there coupled to said electrically alterable material; limiting said electrically alterable material to consist of germanium, with or without dopant atoms; and, confining said electrically alterable material, from its deposition through a predetermined final step that completes said integrated circuit, to temperatures which cause said electrically alterable material to have a smaller crystalline grain size than that of polycrystalline germanium.
Claim 3
Dependent Claim
47 words
A process according to claim 1 and further including another step, after, said confining step, of applying a voltage across said bottom and top electrical leads with a magnitude that causes said germanium to switch irreversibly from an initial resistance between said leads to a reduced resistance.
Claim 4
Dependent Claim
21 words
A process according to claim 2 wherein said initial resistance is at least one thousand times larger than said reduced resistance.
Claim 5
Dependent Claim
26 words
A process according to claim 1 wherein said electrically alterable material includes dopant atoms which are selected from the group consisting of arsenic, phosphorous, and antimony.
Claim 6
Dependent Claim
15 words
A process according to claim 1 wherein said electrically alterable material includes no dopant atoms.
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) | 2000-11-10 | 2001-05-12 | 2001-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-11-10 | 2005-05-12 | 2005-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-11-10 | 2009-05-12 | 2009-11-11 | $7700.00 | Window Closed / Lapsed |