US6010962A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Copper chemical-mechanical-polishing (CMP) dishing
Assignee: Taiwan Semiconductor Manufacturing Co TSMC Ltd
•
Filing: 1999-02-12
•
Granted: 2000-01-04
•
Expires: 2019-02-12
Abstract
Abstract A method is disclosed for forming inlaid copper interconnects in an insulating layer without the normally expected dishing that occurs after chemical-mechanical polishing of the excess copper. This is accomplished by forming a conformal blanket barrier layer over a substrate including a composite groove/hole structure already formed in an insulating layer and then growing a copper seed layer over the barrier layer. A layer of photoresist is next deposited over the substrate filling the composite structure. The photoresist layer, seed layer and the barrier layer are then removed by chemical-mechanical polishing, leaving the seed layer and the barrier layer on the inside walls of the composite structure, however. Then the photoresist is removed from the composite structure, and replaced, in its place, with electroless plated copper, which forms a dome-like protrusion extending from the composite structure. When the substrate is subjected to chemical-mechanical polishing in order to remove the excess copper, the dome-like structure prevents the dishing of the copper metal. In a second embodiment, the seed layer and the barrier layer are chemical-mechanical polished without first depositing a photoresist layer. Copper metal is next selectively formed by electroless plating having a dome-like protrusion, which in turn is removed by chemical-mechanical polishing without the detrimental formation of dishing in the copper metal.
Inventors
- 👤 Chung-Shi Liu
- 👤 Chung-Long Chang
- 👤 Chen-Hua Yu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 14:18
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/056; H10W20/057; H10P; H10P95/00; H10P95/04; H10W20/032; H10W20/054; H10W20/033
Claims Analysis
Total Claims: 49
Claim 1
Independent Claim
267 words
A method of improving chemical-mechanical polishing (CMP) dishing 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; removing said first photoresist layer from said substrate; forming a second photoresist layer over said substrate including said hole pattern; patterning said second photoresist layer with a conductive line groove pattern; etching through said conductive line groove in said second photoresist layer into said ULD layer until etch-stop layer is reached; etching further and transferring said hole pattern from said ULD layer into said LLD layer until a lower level said substructure of said substrate is reached thus forming a composite groove/hole structure; removing said second photoresist layer; forming a barrier layer on the walls, including the bottom wall, of said composite groove/hole structure; forming a seed layer over said barrier layer; forming a third photoresist layer over said substrate including said composite groove/hole structure; chemical-mechanical polishing said third photoresist layer, said seed layer and said barrier layer until ULD top surface is reached; removing said third photoresist layer from said composite groove/hole structure; forming metal in said composite groove/hole structure; and chemical-mechanical polishing said metal.
Claim 2
Independent Claim
267 words
A method of improving chemical-mechanical polishing (CMP) dishing 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; removing said first photoresist layer from said substrate; forming a second photoresist layer over said substrate including said hole pattern; patterning said second photoresist layer with a conductive line groove pattern; etching through said conductive line groove in said second photoresist layer into said ULD layer until etch-stop layer is reached; etching further and transferring said hole pattern from said ULD layer into said LLD layer until a lower level said substructure of said substrate is reached thus forming a composite groove/hole structure; removing said second photoresist layer; forming a barrier layer on the walls, including the bottom wall, of said composite groove/hole structure; forming a seed layer over said barrier layer; forming a third photoresist layer over said substrate including said composite groove/hole structure; chemical-mechanical polishing said third photoresist layer, said seed layer and said barrier layer until ULD top surface is reached; removing said third photoresist layer from said composite groove/hole structure; forming metal in said composite groove/hole structure; and chemical-mechanical polishing said metal.
Claim 3
Dependent Claim
12 words
The method of claim 1, wherein said LLD layer comprises PECVD oxide.
Claim 4
Dependent Claim
18 words
The method of claim 1, wherein said LLD layer has a thickness between about 4000 to 8000 Å.
Claim 5
Dependent Claim
42 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 temperature between about 300 to 420° C.
Claim 6
Dependent Claim
12 words
The method of claim 1, wherein said ULD layer comprises PECVD oxide.
Claim 7
Dependent Claim
18 words
The method of claim 1, wherein said ULD layer has a thickness between about 3000 to 7000 Å.
Claim 8
Dependent Claim
24 words
The method of claim 1, wherein said first photoresist layer over said ULD layer has a thickness between about 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 photomask having said hole pattern.
Claim 10
Dependent Claim
54 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 CO at a flow rate between about 50 to 100 sccm, and C 2 F 6 , at a flow rate between about 30 to 200 sccm.
Claim 11
Dependent Claim
51 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 3 , C 2 F 6 , and Ar at flow rates between about 10 to 30 sccm, 5 to 20 sccm and 50 to 200 sccm, respectively.
Claim 12
Dependent Claim
16 words
The method of claim 1, wherein said first photoresist layer is removed by oxygen plasma ashing.
Claim 13
Dependent Claim
23 words
The method of claim 1, wherein said patterning said second photoresist layer is accomplished with a photomask having said conductive line groove pattern.
Claim 14
Dependent Claim
41 words
The method of claim 1, wherein said etching through said conductive line groove in said second photoresist layer into said LLD layer until etch-stop layer is reached is accomplished with a recipe comprising gases CO and C 2 F 6 .
Claim 15
Dependent Claim
61 words
The method of claim 1, wherein said etching further and transferring from said ULD layer said hole pattern into said LLD layer until a lower level said substructure of said substrate is reached is accomplished with a recipe comprising CO and C 2 F 6 , at flow rates between about 50 to 100 sccm, and 20 to 100 sccm, respectively.
Claim 16
Dependent Claim
18 words
The method of claim 1, wherein said removing said second photoresist layer is accomplished with oxygen plasma ashing.
Claim 17
Dependent Claim
30 words
The method of claim 1, wherein said forming a barrier layer on the walls, including the bottom wall, of said composite hole and groove structure is accomplished by depositing tantalum.
Claim 18
Dependent Claim
18 words
The method of claim 1, wherein said barrier layer has a thickness between about 200 to 400 Å.
Claim 19
Dependent Claim
17 words
The method of claim 1, wherein said forming said seed layer is accomplished by PVD or CVD.
Claim 20
Dependent Claim
18 words
The method of claim 1, wherein said seed layer has a thickness between about 1000 to 2000 Å.
Claim 21
Dependent Claim
19 words
The method of claim 1, wherein said third photoresist layer has a thickness between about 0.8 to 1.5 μm.
Claim 22
Dependent Claim
38 words
The method of claim 1, wherein said chemical-mechanical polishing said third photoresist layer, said seed layer and said barrier layer is accomplished with a slurry comprising Al 2 O 3 +deionized water+an additive compound+H 2 O 2 .
Claim 23
Dependent Claim
18 words
The method of claim 1, wherein said removing said third photoresist layer is accomplished by oxygen plasma ashing.
Claim 24
Dependent Claim
29 words
The method of claim 1, wherein said forming metal in said composite groove/hole structure over said seed layer covering said barrier layer is accomplished by electro-chemical deposition of copper.
Claim 25
Dependent Claim
28 words
The method of claim 1, wherein said chemical-mechanical polishing said metal is accomplished with a slurry comprising Al 2 O 3 +deionized water+an additive+H 2 O 2 .
Claim 26
Independent Claim
245 words
A method of improving chemical-mechanical polishing (CMP) dishing 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; removing said first photoresist layer from said substrate; forming a second photoresist layer over said substrate including said hole pattern; patterning said second photoresist layer with a conductive line groove pattern; etching through said conductive line groove in said second photoresist layer into said ULD layer until etch-stop layer is reached; etching further and transferring said hole pattern from said ULD layer into said LLD layer until a lower level said substructure of said substrate is reached thus forming a composite groove/hole structure; removing said second photoresist layer; forming a barrier layer on the walls, including the bottom wall, of said composite groove/hole structure; forming a seed layer over said barrier layer; chemical-mechanical polishing said seed layer and said barrier layer until ULD top surface is reached; cleaning said composite groove/hole structure; forming metal in said composite groove/hole structure; and chemical-mechanical polishing said metal.
Claim 27
Independent Claim
245 words
A method of improving chemical-mechanical polishing (CMP) dishing 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; removing said first photoresist layer from said substrate; forming a second photoresist layer over said substrate including said hole pattern; patterning said second photoresist layer with a conductive line groove pattern; etching through said conductive line groove in said second photoresist layer into said ULD layer until etch-stop layer is reached; etching further and transferring said hole pattern from said ULD layer into said LLD layer until a lower level said substructure of said substrate is reached thus forming a composite groove/hole structure; removing said second photoresist layer; forming a barrier layer on the walls, including the bottom wall, of said composite groove/hole structure; forming a seed layer over said barrier layer; chemical-mechanical polishing said seed layer and said barrier layer until ULD top surface is reached; cleaning said composite groove/hole structure; forming metal in said composite groove/hole structure; and chemical-mechanical polishing said metal.
Claim 28
Dependent Claim
12 words
The method of claim 25, wherein said LLD layer comprises PECVD oxide.
Claim 29
Dependent Claim
18 words
The method of claim 25, wherein said LLD layer has a thickness between about 4000 to 8000 Å.
Claim 30
Dependent Claim
42 words
The method of claim 25, 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 temperature between about 300 to 420° C.
Claim 31
Dependent Claim
12 words
The method of claim 25, wherein said ULD layer comprises PECVD oxide.
Claim 32
Dependent Claim
18 words
The method of claim 25, wherein said ULD layer has a thickness between about 3000 to 7000 Å.
Claim 33
Dependent Claim
24 words
The method of claim 25, wherein said first photoresist layer over said ULD layer has a thickness between about 1.0 to 1.2 micrometers (μm).
Claim 34
Dependent Claim
21 words
The method of claim 25, wherein said patterning said first photoresist layer is accomplished with a photomask having said hole pattern.
Claim 35
Dependent Claim
48 words
The method of claim 25, wherein said etching through said hole pattern in said first photoresist layer into said ULD layer is accomplished with a recipe comprising CO and C 2 F 6 at flow rates between about 50 to 100 sccm and 30 to 100 sccm, respectively.
Claim 36
Dependent Claim
50 words
The method of claim 25, wherein said etching further said hole pattern into said etch-stop layer is accomplished with a recipe comprising CHF 3 , C 2 F 6 and Ar at flow rates between about 10 to 30 sccm, 5 to 20 sccm and 50 to 200 sccm, respectively.
Claim 37
Dependent Claim
16 words
The method of claim 25, wherein said first photoresist layer is removed by oxygen plasma ashing.
Claim 38
Dependent Claim
23 words
The method of claim 25, wherein said patterning said second photoresist layer is accomplished with a photomask having said conductive line groove pattern.
Claim 39
Dependent Claim
41 words
The method of claim 25, wherein said etching through said conductive line groove in said second photoresist layer into said LLD layer until etch-stop layer is reached is accomplished with a recipe comprising gases CO and C 2 F 6 .
Claim 40
Dependent Claim
60 words
The method of claim 25, wherein said etching further and transferring from said ULD layer said hole pattern into said LLD layer until a lower level said substructure of said substrate is reached is accomplished with a recipe comprising CO and C 2 F 6 at flow rates between about 50 to 100 sccm and 20 to 100 sccm, respectively.
Claim 41
Dependent Claim
18 words
The method of claim 25, wherein said removing said second photoresist layer is accomplished with oxygen plasma ashing.
Claim 42
Dependent Claim
30 words
The method of claim 25, wherein said forming a barrier layer on the walls, including the bottom wall, of said composite hole and trench structure is accomplished by depositing tantalum.
Claim 43
Dependent Claim
18 words
The method of claim 25, wherein said barrier layer has a thickness between about 200 to 400 Å.
Claim 44
Dependent Claim
17 words
The method of claim 25, wherein said forming said seed layer is accomplished by PVD or CVD.
Claim 45
Dependent Claim
18 words
The method of claim 25, wherein said seed layer has a thickness between about 1000 to 2000 Å.
Claim 46
Dependent Claim
33 words
The method of claim 25, wherein said chemical-mechanical polishing said seed layer and said barrier layer is accomplished with a slurry comprising Al 2 O 3 +deionized water (DI)+additive+H 2 O 2 .
Claim 47
Dependent Claim
22 words
The method of claim 25, wherein said cleaning is accomplished with a recipe comprising DI+1% HF+2% NH 4 O 4 +mega-sonic additive.
Claim 48
Dependent Claim
29 words
The method of claim 25, wherein said forming metal in said composite groove/hole structure over said seed layer covering said barrier layer is accomplished by electroless plating of copper.
Claim 49
Dependent Claim
26 words
The method of claim 25, wherein said chemical-mechanical polishing said metal is accomplished with a slurry comprising Al 2 O 3 +DI+additive+H 2 O 2 .
References Cited (Backward Citations)
US5169680A
Cited
US5858877A
Cited
US5654245A
Cited
US5659201A
Cited
US5895261A
Cited
US5674787A
Cited
EP0905768A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-01-03 | 2003-07-05 | 2004-01-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-01-03 | 2007-07-05 | 2008-01-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-01-03 | 2011-07-05 | 2012-01-04 | $7700.00 | Window Closed / Lapsed |