US6274484B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fabrication process for low resistivity tungsten layer with good adhesion to insulator layers
Assignee: Taiwan Semiconductor Manufacturing Co TSMC Ltd
•
Filing: 2000-03-17
•
Granted: 2001-08-14
•
Expires: 2020-03-17
Abstract
Abstract A process for forming a low resistivity tungsten layer, for use as a metal gate structure, or a metal damascene structure, has been developed. The process features initial deposition of a metastable tungsten nitride layer, via a plasma enhanced, or metal organic chemical vapor deposition procedures, resulting in good adhesion, in addition to good step coverage, of the tungsten nitride layer, to underlying or adjacent insulator layers. The high resistivity, tungsten nitride layer is then converted to a lower resistivity tungsten layer, via a rapid thermal anneal procedure, performed in an argon ambient, or in vacuum.
Inventors
- 👤 Ming-Hsing Tsai
- 👤 Sheng-Hsiung Cheu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 16:01
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/064; H10D; H10D64/00; H10D64/01; H10D64/013; H10D64/01302; H10D64/01304; H10D64/01316; H10D64/017
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
100 words
A method of forming a tungsten damascene structure, comprising the steps of: providing an opening in an overlying interlevel dielectric layer, exposing a top surface of a tungsten plug structure, located in a via hole in an underlying interlevel dielectric layer; depositing a tungsten nitride layer, completely filling said opening in said overlying interlevel dielectric layer; performing an anneal procedure to convert said tungsten nitride layer to a tungsten layer; and removing portions of said tungsten layer from the top surface of said overlying ILD layer, to create said tungsten damascene structure in said opening in said overlying ILD layer.
Claim 2
Independent Claim
100 words
A method of forming a tungsten damascene structure, comprising the steps of: providing an opening in an overlying interlevel dielectric layer, exposing a top surface of a tungsten plug structure, located in a via hole in an underlying interlevel dielectric layer; depositing a tungsten nitride layer, completely filling said opening in said overlying interlevel dielectric layer; performing an anneal procedure to convert said tungsten nitride layer to a tungsten layer; and removing portions of said tungsten layer from the top surface of said overlying ILD layer, to create said tungsten damascene structure in said opening in said overlying ILD layer.
Claim 3
Dependent Claim
23 words
The method of claim 1 , wherein said underlying interlevel dielectric layer is comprised of either silicon oxide, or of a borophosphosilicate glass.
Claim 4
Dependent Claim
23 words
The method of claim 1 , wherein said overlying interlevel dielectric layer is comprised of either silicon oxide, or of a borophosphosilicate glass.
Claim 5
Dependent Claim
56 words
The method of claim 1 , wherein said tungsten nitride layer is deposited via a plasma enhanced chemical vapor deposition, (PECVD), or a metal organic chemical vapor deposition, (MOCVD), procedure, to a thickness between about 1000 to 4000 Angstroms, at a temperature between about 150 to 450° C., using WF 6 and NH 3 as reactants.
Claim 6
Dependent Claim
22 words
The method of claim 1 , wherein the resistivity of said tungsten nitride layer is between about 800 to 5000 E-6 ohm-cm.
Claim 7
Dependent Claim
42 words
The method of claim 1 , wherein said anneal procedure, is a rapid thermal anneal procedure, performed at a temperature between about 500 to 800° C., in a argon ambient, or in vacuum, for a time between about 30 to 120 sec.
Claim 8
Dependent Claim
21 words
The method of claim 1 , wherein the resistivity of said tungsten layer is between about 20 to 100 E-6 ohm-cm.
Claim 9
Dependent Claim
49 words
The method of claim 1 , wherein said tungsten damascene structure is formed via removal of said tungsten layer from the top surface of said overlying ILD layer, via a chemical mechanical polishing procedure, or via a selective RIE procedure, using Cl 2 or SF 6 as an etchant.
References Cited (Backward Citations)
US5907188A
Cited
US5923999A
Cited
WO1998023389A1
Cited
US5913145A
Cited
EP0908934A2
Cited
US6103609A
Cited
US5939788A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-08-13 | 2005-02-12 | 2005-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-08-13 | 2009-02-12 | 2009-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-08-13 | 2013-02-12 | 2013-08-14 | $7700.00 | Window Closed / Lapsed |