US6291289B2
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of forming DRAM trench capacitor with metal layer over hemispherical grain polysilicon
Assignee: Mosaid Technologies Inc
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Filing: 1999-06-25
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Granted: 2001-09-18
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Expires: 2019-06-25
Abstract
Abstract Integrated circuitry capacitors and methods of forming the same are described. In accordance with one implementation, a capacitor plate is formed and a conductive layer of material is formed thereove. Preferably, the conductive layer of material is more conductive than the material from which the capacitor plate is formed. In a preferred implementation, the conductive layer of material comprises a titanium or titanium-containing layer. In another preferred implementation, the capacitor plate comprises an inner capacitor plate having an outer surface with a generally roughened surface area. In one aspect of this implementation, the roughened surface area comprises hemispherical grain polysilicon. Capacitors formed in accordance with the invention are particularly well suited for use in dynamic random access memory (DRAM) circuitry.
Inventors
- 👤 Howard E. Rhodes
- 👤 Lyle D. Breiner
- 👤 Philip J. Ireland
- 👤 Trung Tri Doan
- 👤 Gurtej S. Sandhu
- 👤 Sujit Sharan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 01:33
CPC Classifications
H; H10; H10D; H10D1/00; H10D1/60; H10D1/68; H10D1/692; H10D1/711; H10D1/712; H10D1/01; H10D1/041; H10D1/042; H10D1/62; H10D1/66; H10D1/714; H10D1/716; H10B; H10B12/00; H10B12/01; H10B12/02; H10B12/03; H10B12/033; H10B12/0335; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/0698
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
204 words
A method of forming a DRAM storage capacitor comprising: forming a capacitor opening relative to insulative material formed over a substrate, the capacitor opening being disposed elevationally over a node location with which electrical connection is to be made; forming a conductively doped first polysilicon material layer within the capacitor opening to less than completely fill such opening thereby leaving a first remaining capacitor opening, and in electrical communication with the node location, the first polysilicon material layer having a first conductivity; forming a hemispherical grain polysilicon material layer over the first polysilicon material layer, the hemispherical grain polysilicon material layer having an outermost surface with a generally roughened surface area and less than completely filling the first remaining capacitor opening thereby leaving a second remaining capacitor opening; forming a layer comprising a metal material over the hemispherical grain polysilicon material layer's outermost surface, the metal material layer having a second conductivity which is greater than the first conductivity and less than completely filling the second remaining capacitor opening thereby leaving a third remaining capacitor opening; forming a layer comprising a dielectric material over the metal material layer; and forming a cell plate layer over the dielectric material layer to form a storage capacitor.
Claim 2
Independent Claim
204 words
A method of forming a DRAM storage capacitor comprising: forming a capacitor opening relative to insulative material formed over a substrate, the capacitor opening being disposed elevationally over a node location with which electrical connection is to be made; forming a conductively doped first polysilicon material layer within the capacitor opening to less than completely fill such opening thereby leaving a first remaining capacitor opening, and in electrical communication with the node location, the first polysilicon material layer having a first conductivity; forming a hemispherical grain polysilicon material layer over the first polysilicon material layer, the hemispherical grain polysilicon material layer having an outermost surface with a generally roughened surface area and less than completely filling the first remaining capacitor opening thereby leaving a second remaining capacitor opening; forming a layer comprising a metal material over the hemispherical grain polysilicon material layer's outermost surface, the metal material layer having a second conductivity which is greater than the first conductivity and less than completely filling the second remaining capacitor opening thereby leaving a third remaining capacitor opening; forming a layer comprising a dielectric material over the metal material layer; and forming a cell plate layer over the dielectric material layer to form a storage capacitor.
Claim 3
Dependent Claim
33 words
The method of claim 1 , wherein the forming of the layer comprising a metal material comprises chemical vapor depositing a layer comprising titanium over the hemispherical grain polysilicon material layer's outermost surface.
Claim 4
Dependent Claim
32 words
The method of claim 1 wherein the layer comprising metal material and the layer comprising the dielectric material are formed to be at least in partial physical contacting relationship with one another.
Claim 5
Dependent Claim
35 words
The method of claim 1 wherein forming the layer comprising a dielectric material comprises depositing the dielectric material to less than completely fill the third remaining capacitor opening thereby leaving a fourth remaining capacitor opening.
Claim 6
Dependent Claim
64 words
The method of claim 1 wherein, forming the layer comprising a dielectric material comprises depositing the dielectric material to less than completely fill the third remaining capacitor opening thereby leaving a fourth remaining capacitor opening; and forming the cell plate layer comprises depositing the cell plate layer to less than completely fill the fourth remaining capacitor opening thereby leaving a fifth remaining capacitor opening.
Claim 7
Dependent Claim
33 words
The method of claim 1 wherein the forming of the layer comprising a metal material comprises chemical vapor depositing an elemental titanium metal layer over the hemispherical grain polysilicon material layer's outermost surface.
Claim 8
Dependent Claim
32 words
The method of claim 1 wherein the forming of the layer comprising a metal material comprises chemical vapor depositing a titanium silicide layer over the hemispherical grain polysilicon material layer's outermost surface.
Claim 9
Dependent Claim
31 words
The method of claim 1 wherein the forming of the layer comprising a metal material comprises chemical vapor depositing a platinum layer over the hemispherical grain polysilicon material layer's outermost surface.
Claim 10
Dependent Claim
31 words
The method of claim 1 wherein the forming of the layer comprising a metal material comprises chemical vapor depositing a TiN layer over the hemispherical grain polysilicon material layer's outermost surface.
Claim 11
Dependent Claim
32 words
The method of claim 1 wherein the forming of the layer comprising a metal material comprises chemical vapor depositing a metal alloy layer over the hemispherical grain polysilicon material layer's outermost surface.
Claim 12
Dependent Claim
34 words
The method of claim 1 comprising planarizing the first polysilicon material, the hemispherical grain polysilicon and the layer comprising metal material in a common planarizing step prior to forming the layer comprising dielectric material.
Claim 13
Dependent Claim
65 words
The method of claim 1 comprising planarizing the first polysilicon material, the hemispherical grain polysilicon and the layer comprising metal material in a common planarizing step prior to forming the layer comprising dielectric material; and wherein forming the layer comprising a dielectric material comprises depositing the dielectric material to less than completely fill the third remaining capacitor opening thereby leaving a fourth remaining capacitor opening.
Claim 14
Dependent Claim
95 words
The method of claim 11 , comprising planarizing the first polysilicon material, the hemispherical grain polysilicon and the layer comprising metal material in a common planarizing step prior to forming the layer comprising dielectric material; wherein forming the layer comprising a dielectric material comprises depositing the dielectric material to less than completely fill the third remaining capacitor opening thereby leaving a fourth remaining capacitor opening; and wherein forming the cell plate layer comprises depositing the cell plate layer to less than completely fill the fourth remaining capacitor opening thereby leaving a fifth remaining capacitor opening.
References Cited (Backward Citations)
US5486488A
Cited
US5872033A
Cited
US5418180A
Cited
US5665625A
Cited
US5812360A
Cited
US5854734A
Cited
US5597754A
Cited
US5885882A
Cited
US5760434A
Cited
US6010931A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-09-17 | 2005-03-19 | 2005-09-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-09-17 | 2009-03-19 | 2009-09-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-09-17 | 2013-03-19 | 2013-09-18 | $7700.00 | Window Closed / Lapsed |