US6140224A
Expired / Lapsed
US
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Method of forming a tungsten plug
Assignee: Taiwan Semiconductor Manufacturing Co TSMC Ltd
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Filing: 1999-04-19
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Granted: 2000-10-31
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Expires: 2019-04-19
Abstract
Abstract A dielectric layer and a polishing stop layer are respectively formed over a substrate. A glue layer composed of titanium (Ti) is formed along the surface of the dielectric layer. The Ti layer serves as adhension promotion to the subsequent TiN layer. A titanium-nitride (TiN) layer is next formed on the Ti layer to act as a barrier layer. A tungsten layer is deposited on the TiN layer. An etching back step is carried to etch the tungsten layer, therby leaving the tungsten in the contact holes to form the tungsten plug. Non-metal or oxide CMP is used to removes tungsten residues and TiN/Ti layers and the CMP will stop on the polishing stop layer.
Inventors
- 👤 Ching-Fu Lin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 08:24
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/032; H10W20/033; H10W20/062; H10W20/071; H10W20/074; H10W20/40
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
168 words
A method of forming an electrically conducting structure over a semiconductor wafer, said method comprising the steps of: forming a dielectric layer over said semiconductor wafer for isolation; forming a polishing stop layer on said dielectric layer; etching said polishing stop layer and said dielectric layer to form an opening aligned to an underlying conductive region; forming a titanium (Ti) layer on said polishing stop layer and on a surface of said opening to act as an adhesive layer; forming a titanium-nitride (TiN) layer on said Ti layer to act as a barrier layer; forming a tungsten layer on said TiN layer; performing an etching back process to etch said tungsten layer to a surface of said titaniun nitride layer, tungsten residules being formed on a surface of said titanium nitride layer; polishing said titanium nitride layer, said titanium layer by using a chemical mechanical polishing (CMP) with a slury for removing dielectric, thereby removing said tungsten residules and said CMP being stop on said polishing stop layer.
Claim 2
Independent Claim
168 words
A method of forming an electrically conducting structure over a semiconductor wafer, said method comprising the steps of: forming a dielectric layer over said semiconductor wafer for isolation; forming a polishing stop layer on said dielectric layer; etching said polishing stop layer and said dielectric layer to form an opening aligned to an underlying conductive region; forming a titanium (Ti) layer on said polishing stop layer and on a surface of said opening to act as an adhesive layer; forming a titanium-nitride (TiN) layer on said Ti layer to act as a barrier layer; forming a tungsten layer on said TiN layer; performing an etching back process to etch said tungsten layer to a surface of said titaniun nitride layer, tungsten residules being formed on a surface of said titanium nitride layer; polishing said titanium nitride layer, said titanium layer by using a chemical mechanical polishing (CMP) with a slury for removing dielectric, thereby removing said tungsten residules and said CMP being stop on said polishing stop layer.
Claim 3
Dependent Claim
49 words
The method of claim 1, further comprising controlling the total thickness of said titanium and thitanium nitride layers during the formation of said titanium and thitanium nitride layers such that said total thickness with a dimension that is greater than a depth of a dishing formed by said etching.
Claim 4
Dependent Claim
11 words
The method of claim 1, wherein said dielectric layer comprises oxide.
Claim 5
Dependent Claim
12 words
The method of claim 1, wherein said polishing stop layer comprises nitride.
Claim 6
Dependent Claim
12 words
The method of claim 1, wherein said polishing stop layer comprises oxynitride.
Claim 7
Dependent Claim
12 words
The method of claim 1, wherein said polishing stop layer comprises SiC.
Claim 8
Dependent Claim
13 words
The method of claim 1, wherein said polishing stop layer comprises amorphous carbon.
Claim 9
Dependent Claim
13 words
The method of claim 1, wherein said polishing stop layer comprises amorphous CF.
Claim 10
Dependent Claim
15 words
The method of claim 1, wherein said etching back process comprises reactiv ion etching (RIE).
Claim 11
Dependent Claim
14 words
The method of claim 1, wherein said etching back process comprises chemical dry etching.
Claim 12
Dependent Claim
18 words
The method of claim 1, wherein said chemical mechanical polishing (CMP) with said slury for removing oxide material.
Claim 13
Independent Claim
196 words
A method of forming an electrically conducting structure over a semiconductor wafer, said method comprising the steps of: proiding a conductive region on said semiconductor wafer; forming an oxide layer over said semiconductor wafer for isolation; forming a polishing stop layer on said dielectric layer, wherein said polishing stop layer is selected from a group consisting of nitride, oxynitride, SiC, amorphous carbon and amorphous CF; etching said polishing stop layer and said dielectric layer to form an opening aligned to said conductive region; forming a titanium (Ti) layer on said polishing stop layer and on a surface of said opening to act as an adhesive layer; forming a titanium-nitride (TiN) layer on said Ti layer to act as a barrier layer; forming a tungsten layer on said TiN layer; performing an etching back process to etch said tungsten layer to a surface of said titaniun nitride layer, tungsten residules being formed on a surface of said titanium nitride layer; polishing said titanium nitride layer, said titanium layer by using a chemical mechanical polishing (CMP) with a slury for removing oxide material, thereby removing said tungsten residules and said CMP being stop on said polishing stop layer.
Claim 14
Independent Claim
196 words
A method of forming an electrically conducting structure over a semiconductor wafer, said method comprising the steps of: proiding a conductive region on said semiconductor wafer; forming an oxide layer over said semiconductor wafer for isolation; forming a polishing stop layer on said dielectric layer, wherein said polishing stop layer is selected from a group consisting of nitride, oxynitride, SiC, amorphous carbon and amorphous CF; etching said polishing stop layer and said dielectric layer to form an opening aligned to said conductive region; forming a titanium (Ti) layer on said polishing stop layer and on a surface of said opening to act as an adhesive layer; forming a titanium-nitride (TiN) layer on said Ti layer to act as a barrier layer; forming a tungsten layer on said TiN layer; performing an etching back process to etch said tungsten layer to a surface of said titaniun nitride layer, tungsten residules being formed on a surface of said titanium nitride layer; polishing said titanium nitride layer, said titanium layer by using a chemical mechanical polishing (CMP) with a slury for removing oxide material, thereby removing said tungsten residules and said CMP being stop on said polishing stop layer.
Claim 15
Dependent Claim
49 words
The method of claim 12, further comprising controlling the total thickness of said titanium and thitanium nitride layers during the formation of said titanium and thitanium nitride layers such that said total thickness with a dimension that is greater than a depth of a dishing formed by said etching.
Claim 16
Dependent Claim
15 words
The method of claim 12, wherein said etching back process comprises reactiv ion etching (RIE).
Claim 17
Dependent Claim
14 words
The method of claim 12, wherein said etching back process comprises chemical dry etching.
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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) | 2003-10-31 | 2004-05-01 | 2004-10-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-10-31 | 2008-05-01 | 2008-10-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-10-31 | 2012-05-01 | 2012-10-31 | $7700.00 | Window Closed / Lapsed |