Patent US5521119A successfully refreshed from Google Patents.
US5521119A
Expired / Lapsed
US
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Post treatment of tungsten etching back
Assignee: Taiwan Semiconductor Manufacturing Co TSMC Ltd
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Filing: 1994-07-13
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Granted: 1996-05-28
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Expires: 2014-07-13
Abstract
Abstract A new method of metallization without unwanted precipitates using a tungsten plug is achieved. Semiconductor device structures are formed in and on a semiconductor substrate. A contact hole is opened through an insulating layer to the semiconductor substrate. A glue layer is deposited conformally over the surface of the insulating layer and within the contact opening. A layer of tungsten is blanket deposited over the glue layer. The tungsten layer is etched back leaving the tungsten only within the contact opening to form a tungsten plug. The etching back leaves impurities on the surface of the glue layer. Those impurities will react with water or air to form precipitates. The precipitates are removed using a wet chemical etch. The substrate is post treated with argon ion sputtering to prevent future formation of precipitates. A second metal layer is deposited over the tungsten plug and the glue layer to complete the tungsten plug metallization without unwanted precipitates in the fabrication of an integrated circuit.
Inventors
- 👤 Shu-Hui Chen
- 👤 Kuei-Ying Lee
- 👤 Cheng-Yeh Shih
- 👤 Wing-Lang Zang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 09:32
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/056
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
166 words
The method of forming tungsten plug metallization without unwanted precipitates in the fabrication of integrated circuits comprising: providing semiconductor device structures in and on a semiconductor substrate; providing an insulating layer covering said semiconductor device structures wherein a contact hole has been opened through said insulating layer to said semiconductor substrate; depositing a glue layer conformally over the surface of said insulating layer and within said contact opening; depositing a layer of tungsten over said glue layer; etching back said tungsten layer leaving said tungsten only within said contact opening to form said tungsten plug wherein said etching back leaves fluorine, but not sulfur precipitates on the surface of said glue layer; removing said fluorine precipitates with a wet chemical etch; thereafter post treating said substrate wherein said post treatment prevents future formation of said fluorine precipitates; and depositing a second metal layer over said tungsten plug and said glue layer completing said tungsten plug metallization without unwanted precipitates in the fabrication of said integrated circuit.
Claim 2
Independent Claim
166 words
The method of forming tungsten plug metallization without unwanted precipitates in the fabrication of integrated circuits comprising: providing semiconductor device structures in and on a semiconductor substrate; providing an insulating layer covering said semiconductor device structures wherein a contact hole has been opened through said insulating layer to said semiconductor substrate; depositing a glue layer conformally over the surface of said insulating layer and within said contact opening; depositing a layer of tungsten over said glue layer; etching back said tungsten layer leaving said tungsten only within said contact opening to form said tungsten plug wherein said etching back leaves fluorine, but not sulfur precipitates on the surface of said glue layer; removing said fluorine precipitates with a wet chemical etch; thereafter post treating said substrate wherein said post treatment prevents future formation of said fluorine precipitates; and depositing a second metal layer over said tungsten plug and said glue layer completing said tungsten plug metallization without unwanted precipitates in the fabrication of said integrated circuit.
Claim 3
Dependent Claim
42 words
The method of claim 1 wherein said glue layer is composed of a layer of titanium nitride with a thickness of between about 600 to 1200 Angstroms overlying a layer of titanium with a thickness of between about 400 to 800 Angstroms.
Claim 4
Dependent Claim
27 words
The method of claim 1 wherein said glue layer is composed of a layer of titanium nitride with a thickness of between about 600 to 1200 Angstroms.
Claim 5
Dependent Claim
27 words
The method of claim 1 wherein said glue layer is composed of a layer of titanium tungsten with a thickness of between about 600 to 1200 Angstroms.
Claim 6
Dependent Claim
42 words
The method of claim 1 wherein said glue layer is composed of a layer of titanium tungsten with a thickness of between about 600 to 1200 Angstroms overlying a layer of titanium with a thickness of between about 400 to 800 Angstroms.
Claim 7
Dependent Claim
47 words
The method of claim 1 wherein said tungsten layer is etched back using SF 6 and N 2 with a pressure of between about 200 to 400 mTorr, power of between about 150 to 500 watts and bottom electrode temperature of between about 20° to 60° C.
Claim 8
Dependent Claim
23 words
The method of claim 1 wherein said wet chemical etch comprises a hydrofluoric acid solution dip for between about 30 to 60 seconds.
Claim 9
Dependent Claim
30 words
The method of claim 1 wherein said wet chemical etch comprises a dip in a solution of NH 4 OH/H 2 O 2 for between about 1 to 3 minutes.
Claim 10
Dependent Claim
47 words
The method of claim 1 wherein said post treatment comprises sputtering said substrate with argon ions with a dosage of between about 5 E 15 to 6 E 15 atoms/cm2 and an energy of between about 20 to 30 KeV for between about 30 to 50 seconds.
Claim 11
Independent Claim
167 words
The method of forming tungsten plug metallization without unwanted precipitates in the fabrication of integrated circuits comprising: providing semiconductor device structures in and on a semiconductor substrate; providing an insulating layer covering said semiconductor device structures wherein a contact hole has been opened through said insulating layer to said semiconductor substrate; depositing a glue layer conformally over the surface of said insulating layer and within said contact opening; depositing a layer of tungsten over said glue layer; etching back said tungsten layer leaving said tungsten only within said contact opening to form said tungsten plug wherein said etching back leaves fluorine, but not sulfur precipitates on the surface of said glue layer; removing said fluorine precipitates with a wet chemical etch; thereafter sputtering said substrate with argon ions wherein said sputtering prevents future formation of said fluorine precipitates; and depositing a second metal layer over said tungsten plug and said glue layer completing said tungsten plug metallization without unwanted precipitates in the fabrication of said integrated circuit.
Claim 12
Independent Claim
167 words
The method of forming tungsten plug metallization without unwanted precipitates in the fabrication of integrated circuits comprising: providing semiconductor device structures in and on a semiconductor substrate; providing an insulating layer covering said semiconductor device structures wherein a contact hole has been opened through said insulating layer to said semiconductor substrate; depositing a glue layer conformally over the surface of said insulating layer and within said contact opening; depositing a layer of tungsten over said glue layer; etching back said tungsten layer leaving said tungsten only within said contact opening to form said tungsten plug wherein said etching back leaves fluorine, but not sulfur precipitates on the surface of said glue layer; removing said fluorine precipitates with a wet chemical etch; thereafter sputtering said substrate with argon ions wherein said sputtering prevents future formation of said fluorine precipitates; and depositing a second metal layer over said tungsten plug and said glue layer completing said tungsten plug metallization without unwanted precipitates in the fabrication of said integrated circuit.
Claim 13
Dependent Claim
42 words
The method of claim 10 wherein said glue layer is composed of a layer of titanium nitride with a thickness of between about 600 to 1200 Angstroms overlying a layer of titanium with a thickness of between about 400 to 800 Angstroms.
Claim 14
Dependent Claim
27 words
The method of claim 10 wherein said glue layer is composed of a layer of titanium nitride with a thickness of between about 600 to 1200 Angstroms.
Claim 15
Dependent Claim
27 words
The method of claim 10 wherein said glue layer is composed of a layer of titanium tungsten with a thickness of between about 600 to 1200 Angstroms.
Claim 16
Dependent Claim
42 words
The method of claim 10 wherein said glue layer is composed of a layer of titanium tungsten with a thickness of between about 600 to 1200 Angstroms overlying a layer of titanium with a thickness of between about 400 to 800 Angstroms.
Claim 17
Dependent Claim
47 words
The method of claim 10 wherein said tungsten layer is etched back using SF 6 and N 2 with a pressure of between about 200 to 400 mTorr, power of between about 150 to 500 watts and bottom electrode temperature of between about 20° to 60° C.
Claim 18
Dependent Claim
23 words
The method of claim 10 wherein said wet chemical etch comprises a hydrofluoric acid solution dip for between about 30 to 60 seconds.
Claim 19
Dependent Claim
30 words
The method of claim 10 wherein said wet chemical etch comprises a dip in a solution of NH 4 OH/H 2 O 2 for between about 1 to 3 minutes.
Claim 20
Dependent Claim
42 words
The method of claim 10 wherein said argon ions are sputtered with a dosage of between about 5 E 15 to 6 E 15 atoms/cm2 and an energy of between about 20 to 30 KeV for between about 30 to 50 seconds.
Claim 21
Independent Claim
173 words
The method of forming tungsten plug metallization without unwanted precipitates in the fabrication of integrated circuits comprising: providing semiconductor device structures in and on a semiconductor substrate; providing an insulating layer covering said semiconductor device structures wherein a contact hole has been opened through said insulating layer to said semiconductor substrate; depositing a glue layer conformally over the surface of said insulating layer and within said contact opening; depositing a layer of tungsten over said glue layer; etching back said tungsten layer using SF 6 and N 2 leaving said tungsten only within said contact opening to form said tungsten plug wherein said etching back leaves fluorine but not sulfur precipitates on the surface of said glue layer; removing said fluorine precipitates with a wet chemical etch; thereafter sputtering said substrate with argon ions wherein said sputtering prevents future formation of said fluorine precipitates; and depositing a second metal layer over said tungsten plug and said glue layer completing said tungsten plug metallization without unwanted precipitates in the fabrication of said integrated circuit.
Claim 22
Independent Claim
173 words
The method of forming tungsten plug metallization without unwanted precipitates in the fabrication of integrated circuits comprising: providing semiconductor device structures in and on a semiconductor substrate; providing an insulating layer covering said semiconductor device structures wherein a contact hole has been opened through said insulating layer to said semiconductor substrate; depositing a glue layer conformally over the surface of said insulating layer and within said contact opening; depositing a layer of tungsten over said glue layer; etching back said tungsten layer using SF 6 and N 2 leaving said tungsten only within said contact opening to form said tungsten plug wherein said etching back leaves fluorine but not sulfur precipitates on the surface of said glue layer; removing said fluorine precipitates with a wet chemical etch; thereafter sputtering said substrate with argon ions wherein said sputtering prevents future formation of said fluorine precipitates; and depositing a second metal layer over said tungsten plug and said glue layer completing said tungsten plug metallization without unwanted precipitates in the fabrication of said integrated circuit.
Claim 23
Dependent Claim
43 words
The method of claim 19 wherein said argon ions are sputtered with a dosage of between about 5 E 15 to 6 E 15 atoms/cm 2 and an energy of between about 20 to 30 KeV for between about 30 to 50 seconds.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-05-28 | 1999-11-27 | 2000-05-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-05-28 | 2003-11-27 | 2004-05-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-05-28 | 2007-11-27 | 2008-05-28 | $7700.00 | Window Closed / Lapsed |