US6232175B1
Expired / Lapsed
US
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Method of manufacturing double-recess crown-shaped DRAM capacitor
Assignee: Taiwan Semiconductor Manufacturing Co TSMC Ltd
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Filing: 1999-12-17
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Granted: 2001-05-15
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Expires: 2019-12-17
Abstract
Abstract A double recess crown-shaped DRAM capacitor is formed in a simplified process. A dielectric layer is formed over a substrate. Using photolithographic and etching techniques, a contact opening is formed in the dielectric layer. A conductive layer is formed over the dielectric layer filling the contact opening to form a conductive plug. A second dielectric layer is formed over the conductive layer. Again using photolithographic and etching techniques, the second dielectric layer is patterned to form a trapezoidal-shaped dielectric layer. An organic bottom anti-reflective coating (organic BARC) is coated over the trapezoidal-shaped dielectric layer and the conductive layer. Organic BARC above the trapezoidal-shaped dielectric layer is removed. Using the organic BARC as an etching mask, the trapezoidal-shaped dielectric layer is etched to form triangular-shaped dielectric layers and a trench in the conductive layer. The residual organic BARC is completely removed. Using the triangular-shaped dielectric layers as a hard etching mask, two types of trenches each having a different depth are formed in the conductive layer. The triangular-shaped dielectric layers are removed to form a double-recess lower electrode. Hemispherical silicon grains are grown over the interior surface of the double-recess lower electrode as well as the external sidewalls. Finally, a conformal dielectric layer and a conformal conductive layer are sequentially formed over the surface of the double-recess lower electrode.
Inventors
- 👤 Yuan-Hung Liu
- 👤 Bor-Wen Chan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 11:18
CPC Classifications
H; H10; H10D; H10D1/00; H10D1/01; H10D1/041; H10D1/043; H10D1/60; H10D1/68; H10D1/692; H10D1/711; H10D1/716; H10B; H10B12/00; H10B12/01; H10B12/02; H10B12/03; H10B12/033; H10P; H10P50/00; H10P50/71
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
233 words
A method for forming a double-recess crown-shaped capacitor of a dynamic random access memory (DRAM), comprising the steps of: providing a substrate; forming a first dielectric layer and a conductive plug; forming a first conductive layer over the first dielectric layer; forming a second dielectric layer over the first conductive layer; patterning the second dielectric layer to form a patterned third dielectric layer; forming an organic bottom anti-reflective coating (organic BARC) over the patterned third dielectric layer and the first conductive layer; removing the organic BARC above the patterned third dielectric layer and a portion of the patterned third dielectric layer to form a patterned fourth dielectric layer within the patterned third dielectric layer and a first trench in the first conductive layer; removing the organic BARC; etching to form a second trench under the first trench and a third trench in the first conductive layer using the patterned fourth dielectric layer as an etching mask, wherein the second trench exposes a portion of the first dielectric layer while the third trench is not deep enough to expose the first dielectric layer; removing the patterned fourth dielectric layer such that the first conductive layer having the second trench and the third trench thereon forms a double-recess lower electrode; forming a fifth dielectric layer over the exposed surface of the double-recess lower electrode; and forming a second conductive layer over the fifth dielectric layer.
Claim 2
Independent Claim
233 words
A method for forming a double-recess crown-shaped capacitor of a dynamic random access memory (DRAM), comprising the steps of: providing a substrate; forming a first dielectric layer and a conductive plug; forming a first conductive layer over the first dielectric layer; forming a second dielectric layer over the first conductive layer; patterning the second dielectric layer to form a patterned third dielectric layer; forming an organic bottom anti-reflective coating (organic BARC) over the patterned third dielectric layer and the first conductive layer; removing the organic BARC above the patterned third dielectric layer and a portion of the patterned third dielectric layer to form a patterned fourth dielectric layer within the patterned third dielectric layer and a first trench in the first conductive layer; removing the organic BARC; etching to form a second trench under the first trench and a third trench in the first conductive layer using the patterned fourth dielectric layer as an etching mask, wherein the second trench exposes a portion of the first dielectric layer while the third trench is not deep enough to expose the first dielectric layer; removing the patterned fourth dielectric layer such that the first conductive layer having the second trench and the third trench thereon forms a double-recess lower electrode; forming a fifth dielectric layer over the exposed surface of the double-recess lower electrode; and forming a second conductive layer over the fifth dielectric layer.
Claim 3
Dependent Claim
22 words
The method of claim 1 , wherein materials for forming the second dielectric layer and the first dielectric layer are the same.
Claim 4
Dependent Claim
26 words
The method of claim 1 , wherein the step of forming the first and the second dielectric layers includes depositing silicon oxide by chemical vapor deposition.
Claim 5
Dependent Claim
44 words
The method of claim 1 , wherein depths of the first trench and the third trench are each smaller than a thickness of the first conductive layer, while depth of the second trench and thickness of the first conductive layer are almost the same.
Claim 6
Independent Claim
189 words
A method for forming a lower electrode of a double-recess crown-shaped capacitor, comprising the steps of: providing a substrate; forming a first dielectric layer and a conductive plug; forming a first conductive layer over the first dielectric layer; forming a second dielectric layer over the first conductive layer; patterning the second dielectric layer to form a trapezoidal-shaped third dielectric layer; forming an organic bottom anti-reflective coating (organic BARC) over the trapezoidal-shaped third dielectric layer and the first conductive layer; removing the organic BARC above the trapezoidal-shaped third dielectric layer and then removing a portion of the trapezoidal-shaped third dielectric layer to form a triangular-shaped fourth dielectric layer and a first trench in the first conductive layer, using the organic BARC as a mask; removing the organic BARC; etching to form a second trench under the first trench and a third trench in the first conductive layer using the triangular-shaped fourth dielectric layer as an etching mask, wherein the second trench exposes a portion of the first dielectric layer while the third trench is not deep enough to expose the first dielectric layer; and removing the triangular-shaped fourth dielectric layer.
Claim 7
Independent Claim
189 words
A method for forming a lower electrode of a double-recess crown-shaped capacitor, comprising the steps of: providing a substrate; forming a first dielectric layer and a conductive plug; forming a first conductive layer over the first dielectric layer; forming a second dielectric layer over the first conductive layer; patterning the second dielectric layer to form a trapezoidal-shaped third dielectric layer; forming an organic bottom anti-reflective coating (organic BARC) over the trapezoidal-shaped third dielectric layer and the first conductive layer; removing the organic BARC above the trapezoidal-shaped third dielectric layer and then removing a portion of the trapezoidal-shaped third dielectric layer to form a triangular-shaped fourth dielectric layer and a first trench in the first conductive layer, using the organic BARC as a mask; removing the organic BARC; etching to form a second trench under the first trench and a third trench in the first conductive layer using the triangular-shaped fourth dielectric layer as an etching mask, wherein the second trench exposes a portion of the first dielectric layer while the third trench is not deep enough to expose the first dielectric layer; and removing the triangular-shaped fourth dielectric layer.
Claim 8
Dependent Claim
22 words
The method of claim 5 , wherein materials for forming the second dielectric layer and the first dielectric layer are the same.
Claim 9
Dependent Claim
26 words
The method of claim 5 , wherein the step of forming the first and the second dielectric layer includes depositing silicon oxide by chemical vapor deposition.
Claim 10
Dependent Claim
43 words
The method of claim 5 , wherein depths of the first trench and the third trench are smaller than a thickness of the first conductive layer, while depth of the second trench and thickness of the first conductive layer are almost the same.
References Cited (Backward Citations)
US5474951A
Cited
US5668039A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-05-14 | 2004-11-13 | 2005-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-05-14 | 2008-11-13 | 2009-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-05-14 | 2012-11-13 | 2013-05-15 | $7700.00 | Window Closed / Lapsed |