US6042999A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Robust dual damascene process
Assignee: Taiwan Semiconductor Manufacturing Co TSMC Ltd
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Filing: 1998-05-07
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Granted: 2000-03-28
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Expires: 2018-05-07
Abstract
Abstract A robust dual damascene process is disclosed where the substructure in a substrate is protected from damage caused by multiple etchings required in a damascene process by filling a contact or via hole opening with a protective material prior to the forming of the conductive line opening of the damascene structure having an etch-stop layer separating a lower and an upper dielectric layer. In the first embodiment, the protective material is partially removed from the hole opening reaching the substructure prior to the forming of the upper conductive line opening by etching. In the second embodiment, the protective material in the hole is removed at the same time the upper conductive line opening is formed by etching. In a third embodiment, the disclosed process is applied without the need of an etch-stop layer for the dual damascene process of this invention.
Inventors
- 👤 Cheng-Tung Lin
- 👤 Yu-Hua Lee
- 👤 Jenn Ming Huang
- 👤 Cheng-Ming Wu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 08:09
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/071; H10W20/081; H10W20/084; H10W20/085; G; G03; G03F; G03F7/00; G03F7/0035; H10P; H10P76/00; H10P76/20; H10P76/204; H10P76/2041; H10P76/2043
Claims Analysis
Total Claims: 43
Claim 1
Independent Claim
295 words
A method of forming a dual damascene structure with a protective coating in hole openings comprising the steps of: providing a semiconductor substrate having a substructure comprising devices formed in said substrate and a metal layer formed thereon; forming a lower level dielectric (LLD) layer over said substrate; forming an etch-stop layer over said LLD layer; forming an upper level dielectric (ULD) layer over said etch-stop layer; forming a first photoresist layer over said ULD layer; patterning said first photoresist layer with a hole pattern; etching through said hole pattern in said first photoresist layer into said ULD layer; etching further said hole pattern into said etch-stop layer; etching further said hole pattern into said LLD layer until a lower level said substructure of said substrate is reached; removing said first photoresist layer from said substrate; forming a bottom-anti-reflective coating (BARC) over said substrate and filling said hole opening with said BARC; forming a second photoresist layer over said BARC over said substrate including said hole opening; patterning said second photoresist layer with a conductive line opening pattern; performing a timed-etch through said conductive line opening in said second photoresist layer to remove said BARC from said hole opening in said ULD layer and partially from said hole opening in said LLD layer; etching through said conductive line opening in said second photoresist layer into said ULD layer until etch-stop layer is reached; removing said second photoresist layer; removing remaining said BARC from said hole opening in said LLD layer; forming metal in said conductive line opening in said ULD layer and hole opening through said etch-stop layer and in said LLD layer; and removing said metal from the surface of said substrate for subsequent process steps to complete the fabrication of a semiconductor substrate.
Claim 2
Independent Claim
295 words
A method of forming a dual damascene structure with a protective coating in hole openings comprising the steps of: providing a semiconductor substrate having a substructure comprising devices formed in said substrate and a metal layer formed thereon; forming a lower level dielectric (LLD) layer over said substrate; forming an etch-stop layer over said LLD layer; forming an upper level dielectric (ULD) layer over said etch-stop layer; forming a first photoresist layer over said ULD layer; patterning said first photoresist layer with a hole pattern; etching through said hole pattern in said first photoresist layer into said ULD layer; etching further said hole pattern into said etch-stop layer; etching further said hole pattern into said LLD layer until a lower level said substructure of said substrate is reached; removing said first photoresist layer from said substrate; forming a bottom-anti-reflective coating (BARC) over said substrate and filling said hole opening with said BARC; forming a second photoresist layer over said BARC over said substrate including said hole opening; patterning said second photoresist layer with a conductive line opening pattern; performing a timed-etch through said conductive line opening in said second photoresist layer to remove said BARC from said hole opening in said ULD layer and partially from said hole opening in said LLD layer; etching through said conductive line opening in said second photoresist layer into said ULD layer until etch-stop layer is reached; removing said second photoresist layer; removing remaining said BARC from said hole opening in said LLD layer; forming metal in said conductive line opening in said ULD layer and hole opening through said etch-stop layer and in said LLD layer; and removing said metal from the surface of said substrate for subsequent process steps to complete the fabrication of a semiconductor substrate.
Claim 3
Dependent Claim
16 words
The method of claim 1, wherein said LLD layer comprises silicon oxide, silicon nitride or silicon-oxynitride.
Claim 4
Dependent Claim
17 words
The method of claim 1, wherein said LLD layer has a thickness between 8,000 to 15,000 Å.
Claim 5
Dependent Claim
62 words
The method of claim 1, wherein said forming an etch-stop layer over said LLD layer is accomplished by reacting dichlorosilane (SiCl 2 H 2 ) with ammonia (NH 3 ) in an LPCVD at a pressure between about 0.25 to 1.0 torr, temperature between 650 to 750° C. and at flow rates between 80 to 120 standard cubic centimeters per minute (sccm).
Claim 6
Dependent Claim
16 words
The method of claim 1, wherein said ULD layer comprises silicon oxide, silicon nitride or silicon-oxynitride.
Claim 7
Dependent Claim
17 words
The method of claim 1, wherein said ULD layer has a thickness between 8,000 to 5,000 Å.
Claim 8
Dependent Claim
23 words
The method of claim 1, wherein said first photoresist layer over said ULD layer has a thickness between 1.0 to 1.2 micrometers (μm).
Claim 9
Dependent Claim
21 words
The method of claim 1, wherein said patterning said first photoresist layer is accomplished with a mask having said hole pattern.
Claim 10
Dependent Claim
32 words
The method of claim 1, wherein said etching through said hole pattern in said first photoresist layer into said ULD layer is accomplished with a recipe comprising CHF 4 /CHF 3 gases.
Claim 11
Dependent Claim
27 words
The method of claim 1, wherein said etching further said hole pattern into said etch-stop layer is accomplished with a recipe comprising CHF 4 /CHF 3 gases.
Claim 12
Dependent Claim
38 words
The method of claim 1, wherein said etching further said hole pattern in said LLD layer until a lower level said substructure of said substrate is reached is accomplished with a recipe comprising CHF 4 /CHF 3 gases.
Claim 13
Dependent Claim
15 words
The method of claim 1, wherein said first photoresist layer is removed by oxygen ashing.
Claim 14
Dependent Claim
30 words
The method of claim 1, wherein said forming a bottom-anti-reflective coating (BARC) over said substrate and filling said hole opening with said BARC is accomplished by silicon-oxynitride of organic BARC.
Claim 15
Dependent Claim
21 words
The method of claim 1, wherein said second photoresist layer over said BARC has a thickness between 700 to 1300 Å.
Claim 16
Dependent Claim
23 words
The method of claim 1, wherein said patterning said second photoresist layer is accomplished with a mask having said conductive line opening pattern.
Claim 17
Dependent Claim
65 words
The method of claim 1, wherein said timed-etch through said conductive line opening in said second photoresist layer to remove said BARC from said hole opening in said ULD layer is accomplished with a recipe comprising gases O 2 with a flow rate between 10 to 100 sccm, N 2 between 10 to 100 sccm, and for a period of between 30 to 60 seconds.
Claim 18
Dependent Claim
22 words
The method of claim 16, wherein said removing said metal from the surface of said substrate is accomplished by chemical mechanical polishing.
Claim 19
Dependent Claim
54 words
The method of claim 1, wherein said etching through said conductive line opening in said second photoresist layer into said LLD layer until etch-stop layer is reached is accomplished with a recipe comprising gases CF 4 with a flow rate between 10 to 100 sccm, CHF 3 between about 10 to 100 sccm, respectively.
Claim 20
Dependent Claim
17 words
The method of claim 1, wherein said removing said second photoresist layer is accomplished with oxygen ashing.
Claim 21
Dependent Claim
35 words
The method of claim 1, wherein said removing remaining said BARC from said hole opening in said LLD layer is accomplished with a wet-etch solution comprising H 2 SO 4 /H 2 O 2 .
Claim 22
Dependent Claim
36 words
The method of claim 1, wherein said forming metal in said conductive line opening in said ULD layer and hole opening through said etch-stop layer and in said LLD layer is accomplished by depositing aluminum copper.
Claim 23
Independent Claim
284 words
A method of forming a dual damascene structure with a protective coating in hole openings comprising the steps of: providing a semiconductor substrate having a substructure comprising devices formed in said substrate and a metal layer formed thereon; forming a lower level dielectric (LLD) layer over said substrate; forming an etch-stop layer over said LLD layer; forming an upper level dielectric (ULD) layer over said etch-stop layer; forming a first photoresist layer over said ULD layer; patterning said first photoresist layer with a hole pattern; etching through said hole pattern in said first photoresist layer into said ULD layer; etching further said hole pattern into said etch-stop layer; etching further said hole pattern in said LLD layer until a lower level said substructure of said substrate is reached; removing said first photoresist layer from said substrate; depositing a bottom-anti-reflective coating (BARC) over said substrate filling said hole opening with said BARC; forming a second photoresist layer over said BARC over said substrate including said hole opening; patterning said second photoresist layer with a conductive line opening pattern; performing a simultaneous etch of both said BARC and said ULD layer through said conductive line opening in said second photoresist layer until said etch-stop layer is reached, thus leaving a portion of said BARC in said hole opening in said LLD layer; removing said second photoresist layer; removing said portion of said BARC from said hole opening in said LLD layer; depositing metal in said conductive line opening in said ULD layer and hole opening through said etch-stop layer and in said LLD layer; and removing said metal from the surface of said substrate for subsequent process steps to complete the fabrication of a semiconductor substrate.
Claim 24
Independent Claim
284 words
A method of forming a dual damascene structure with a protective coating in hole openings comprising the steps of: providing a semiconductor substrate having a substructure comprising devices formed in said substrate and a metal layer formed thereon; forming a lower level dielectric (LLD) layer over said substrate; forming an etch-stop layer over said LLD layer; forming an upper level dielectric (ULD) layer over said etch-stop layer; forming a first photoresist layer over said ULD layer; patterning said first photoresist layer with a hole pattern; etching through said hole pattern in said first photoresist layer into said ULD layer; etching further said hole pattern into said etch-stop layer; etching further said hole pattern in said LLD layer until a lower level said substructure of said substrate is reached; removing said first photoresist layer from said substrate; depositing a bottom-anti-reflective coating (BARC) over said substrate filling said hole opening with said BARC; forming a second photoresist layer over said BARC over said substrate including said hole opening; patterning said second photoresist layer with a conductive line opening pattern; performing a simultaneous etch of both said BARC and said ULD layer through said conductive line opening in said second photoresist layer until said etch-stop layer is reached, thus leaving a portion of said BARC in said hole opening in said LLD layer; removing said second photoresist layer; removing said portion of said BARC from said hole opening in said LLD layer; depositing metal in said conductive line opening in said ULD layer and hole opening through said etch-stop layer and in said LLD layer; and removing said metal from the surface of said substrate for subsequent process steps to complete the fabrication of a semiconductor substrate.
Claim 25
Dependent Claim
16 words
The method of claim 22, wherein said LLD layer comprises silicon oxide, silicon nitride or silicon-oxynitride.
Claim 26
Dependent Claim
18 words
The method of claim 22, wherein said LLD layer has a thickness between about 8,000 to 15,000 Å.
Claim 27
Dependent Claim
61 words
The method of claim 22, wherein said forming an etch-stop layer over said LLD layer is accomplished by reacting dichlorosilane (SiCl 2 H 2 ) with ammonia (NH 3 ) in an LPCVD at a pressure between 0.25 to 1.0 torr, temperature between 650 to 750° C. and at flow rates between 80 to 120 standard cubic centimeters per minute (sccm).
Claim 28
Dependent Claim
16 words
The method of claim 22, wherein said ULD layer comprises silicon oxide, silicon nitride or silicon-oxynitride.
Claim 29
Dependent Claim
22 words
The method of claim 26, wherein said removing said metal from the surface of said substrate is accomplished by chemical mechanical polishing.
Claim 30
Dependent Claim
17 words
The method of claim 22, wherein said ULD layer has a thickness between 8,000 to 15,000 Å.
Claim 31
Dependent Claim
23 words
The method of claim 22, wherein said first photoresist layer over said ULD layer has a thickness between 1.0 to 1.2 micrometers (μm).
Claim 32
Dependent Claim
21 words
The method of claim 22, wherein said patterning said first photoresist layer is accomplished with a mask having said hole pattern.
Claim 33
Dependent Claim
32 words
The method of claim 22, wherein said etching through said hole pattern in said first photoresist layer into said ULD layer is accomplished with a recipe comprising CHF 4 /CHF 3 .
Claim 34
Dependent Claim
27 words
The method of claim 22, wherein said etching further said hole pattern into said etch-stop layer is accomplished with a recipe comprising CHF 4 /CHF 3 .
Claim 35
Dependent Claim
38 words
The method of claim 22, wherein said etching further said hole pattern in said LLD layer until a lower level said substructure of said substrate is reached is accomplished with a recipe comprising CHF 4 /CHF 3 .
Claim 36
Dependent Claim
15 words
The method of claim 22, wherein said first photoresist layer is removed by oxygen ashing.
Claim 37
Dependent Claim
30 words
The method of claim 22, wherein said forming a bottom-anti-reflective coating (BARC) over said substrate and filling said hole opening with said BARC is accomplished by silicon-oxynitride or organic BARC.
Claim 38
Dependent Claim
21 words
The method of claim 22, wherein said second photoresist layer over said BARC has a thickness between 700 to 1300 Å.
Claim 39
Dependent Claim
23 words
The method of claim 22, wherein said patterning said second photoresist layer is accomplished with a mask having said conductive line opening pattern.
Claim 40
Dependent Claim
85 words
The method of claim 22, wherein said performing a simultaneous etch of both said BARC and said ULD layer through said conductive line opening in said second photoresist layer until said etch-stop layer is reached, thus leaving a portion of said BARC in said hole opening in said LLD layer is accomplished with a recipe comprising gases CF 4 with a flow rate between 10 to 100 sccm, CHF 3 between 10 to 100 sccm, and for a period of between 90 to 150 seconds.
Claim 41
Dependent Claim
17 words
The method of claim 22, wherein said removing said second photoresist layer is accomplished with oxygen ashing.
Claim 42
Dependent Claim
38 words
The method of claim 22, wherein said removing remaining said portion of said BARC from said hole opening in said LLD layer is accomplished with a wet-etch solution comprising H 2 SO 4 /H 2 O 2 .
Claim 43
Dependent Claim
36 words
The method of claim 22, wherein said forming metal in said conductive line opening in said ULD layer and hole opening through said etch-stop layer and in said LLD layer is accomplished by depositing aluminum copper.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-03-28 | 2003-09-27 | 2004-03-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-03-28 | 2007-09-27 | 2008-03-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-03-28 | 2011-09-27 | 2012-03-28 | $7700.00 | Window Closed / Lapsed |