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Method of making a DRAM capacitor for use as an programmable antifuse for redundancy repair/options on a DRAM

Assignee: Micron Technology Inc
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Filing: 1991-10-04
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Granted: 1992-05-05
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Expires: 2011-10-04
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Abstract

Abstract The invention is directed to a concept to use a 3-dimensional DRAM capacitor as a one-time non-volatile programming element (programmable antifuse) to make redundancy repair and/or to select other options on a DRAM. The programmable element of the present invention provides some significant advantages, such as a lower programming voltage, which allows use of the DRAM's existing operating supply, and requiring only half of the operating voltage to test the element once programming is accomplished. The lower programming voltage allows for redundancy repair of defective DRAM cells (or selecting other options) to be made after the DRAM die is packaged including after it is installed at a customer's site.

Inventors

  • 👤 Tyler A. Lowrey
  • 👤 Kevin G. Duesman
  • 👤 Eugene H. Cloud

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-02 13:39
CPC Classifications
H; H10; H10B; H10B12/00; H10B12/01; H10B12/02; H10B12/03; H10B12/033; H10D; H10D84/00; H10D84/90; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/064; H10W20/065; H10W20/40; H10W20/49; H10W20/491

Claims Analysis

Total Claims: 13
Claim 1
Independent Claim 249 words
A process to form a programmable 3-dimensional antifuse element in a dynamic random access memory fabricated on a starting substrate, said process comprising: (a) forming a isolative dielectric layer over an existing surface of said starting substrate, said starting substrate surface having first and second conductors therein; (b) masking and etching a first buried contact opening thereby exposing a portion of said first conductor; (c) placing a first conductive material superjacent said isolative dielectric layer and said first conductor's xposed portion thereby forming a first buried contact between said first conductive material and said first conductor's exposed portion; (d) patterning said first conductive material thereby leaving a patterened portion of said first conductive material aligned about said first buried contact; (e) forming a dielectric layer superjacent said patterened first conductive material and said isolative dielectric layer; (f) masking and etching a second buried contact opening thereby exposing a portion of said second conductor; (g) placing a second conductive material superjacent said dielectric layer and said second conductor's exposed portion thereby forming a second buried contact between said second conductive material and said second conductor's exposed portion; and (h) patterning said second conductive material thereby leaving a patterned portion of said second conductive material aligned about said contact and extending to and overlying said first conductive material, said patterned first conductive material, the portion of said patterned second conductive material overlying said first patterned conductive material and the portion of said dielectric residing therebetween forming said programmable 3-dimensional antifuse structure.
Claim 2
Dependent Claim 249 words
A process to form a programmable 3-dimensional antifuse element in a dynamic random access memory fabricated on a starting substrate, said process comprising: (a) forming a isolative dielectric layer over an existing surface of said starting substrate, said starting substrate surface having first and second conductors therein; (b) masking and etching a first buried contact opening thereby exposing a portion of said first conductor; (c) placing a first conductive material superjacent said isolative dielectric layer and said first conductor's xposed portion thereby forming a first buried contact between said first conductive material and said first conductor's exposed portion; (d) patterning said first conductive material thereby leaving a patterened portion of said first conductive material aligned about said first buried contact; (e) forming a dielectric layer superjacent said patterened first conductive material and said isolative dielectric layer; (f) masking and etching a second buried contact opening thereby exposing a portion of said second conductor; (g) placing a second conductive material superjacent said dielectric layer and said second conductor's exposed portion thereby forming a second buried contact between said second conductive material and said second conductor's exposed portion; and (h) patterning said second conductive material thereby leaving a patterned portion of said second conductive material aligned about said contact and extending to and overlying said first conductive material, said patterned first conductive material, the portion of said patterned second conductive material overlying said first patterned conductive material and the portion of said dielectric residing therebetween forming said programmable 3-dimensional antifuse structure.
Claim 3
Dependent Claim 18 words
The process as recited in claim 1, wherein said dynamic random access memory fabrication uses stacked capacitor technology.
Claim 4
Dependent Claim 18 words
The process as recited in claim 1, wherein said dynamic random access memory fabrication uses trench capacitor technology.
Claim 5
Dependent Claim 18 words
The process as recited in claim 1, wherein said first and second conductive plates comprise conductively doped polysilicon.
Claim 6
Dependent Claim 18 words
The process as recited in claim 1, wherein said first and second conductive plates comprise a refractory metal.
Claim 7
Dependent Claim 13 words
The process as recited in claim 5, wherein said refractory metal is tantalum.
Claim 8
Dependent Claim 13 words
The process as recited in claim 5, wherein said refractory metal is titanium.
Claim 9
Dependent Claim 13 words
The process as recited in claim 1, wherein said capacitor dielectric comprises oxide.
Claim 10
Dependent Claim 18 words
The process as recited in claim 1, wherein said said capacitor dielectric is 25 to 100 Å thick.
Claim 11
Dependent Claim 13 words
The process as recited in claim 1, wherein said capacitor dielectric comprises nitride.
Claim 12
Dependent Claim 16 words
The process as recited in claim 1, wherein said capacitor dielectric comprises a multiple layered dielectric.
Claim 13
Dependent Claim 15 words
The process as recited in claim 11, wherein said multiple layered dielectric comprises oxide/nitride/oxide layers.

References Cited (Backward Citations)

US4543594A Cited
US4635345A Cited
US4899205A Cited
US4943538A Cited
US4881114A Cited
US5017510A Cited
US5070384A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1995-05-05 1995-11-04 1996-05-05 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1999-05-05 1999-11-04 2000-05-05 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2003-05-05 2003-11-04 2004-05-05 $7700.00 Window Closed / Lapsed

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