US6140237A
Expired / Lapsed
US
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Damascene process for forming coplanar top surface of copper connector isolated by barrier layers in an insulating layer
Assignee: GlobalFoundries Singapore Pte 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 structure and method for making copper interconnections in an integrated circuit are described. The structure is a damascene copper connector whose upper surface is coplanar with the upper surface of the insulating layer in which it is embedded. Out-diffusion of copper from the connector is prevented by two barrier layers. One is located at the interface between the connector and the insulating layer while the second barrier is an insulating layer which covers the upper surface of the connector. The damascene process involves filling a trench in the surface of the insulator with copper and then removing the excess by chem.-mech. polishing. Since photoresist is never in direct contact with the copper the problem of copper oxidation during resist ashing has been effectively eliminated.
Inventors
- 👤 Lap Chan
- 👤 Jia Zhen Zheng
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:01
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/071; H10W20/074; H10W20/077; H10W20/031; H10W20/032; H10W20/033; H10W20/40; H10W20/41; H10W20/425
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
212 words
A method of forming an electrical connector in an integrated circuit comprising: forming a first insulating layer, having a top surface and a bottom surface on a silicon substrate, forming a trench in said first insulating layer, said trench having walls and a bottom, said bottom of said trench being a distance above said bottom surface of said first insulating layer, forming a barrier layer covering said bottom of said walls and said bottom surface of said trench, forming a copper connector over said barrier layer in said trench, said copper connector having upper and lower surfaces, such that the upper surface of said copper connector is at the level of said upper surface of said first insulating layer and said lower surface of said copper connector is said distance above the bottom surface of said first insulating layer plus the thickness of said barrier layer, forming a second, insulating, barrier layer on said upper surface of said copper connector and forming said second, insulating, barrier layer on said top surface of said first insulating layer aside from said copper connector, and forming a second insulating layer on said second barrier layer, whereby said first barrier layer forms a first interface is formed between said copper connector and said first insulating layer.
Claim 2
Independent Claim
212 words
A method of forming an electrical connector in an integrated circuit comprising: forming a first insulating layer, having a top surface and a bottom surface on a silicon substrate, forming a trench in said first insulating layer, said trench having walls and a bottom, said bottom of said trench being a distance above said bottom surface of said first insulating layer, forming a barrier layer covering said bottom of said walls and said bottom surface of said trench, forming a copper connector over said barrier layer in said trench, said copper connector having upper and lower surfaces, such that the upper surface of said copper connector is at the level of said upper surface of said first insulating layer and said lower surface of said copper connector is said distance above the bottom surface of said first insulating layer plus the thickness of said barrier layer, forming a second, insulating, barrier layer on said upper surface of said copper connector and forming said second, insulating, barrier layer on said top surface of said first insulating layer aside from said copper connector, and forming a second insulating layer on said second barrier layer, whereby said first barrier layer forms a first interface is formed between said copper connector and said first insulating layer.
Claim 3
Dependent Claim
32 words
The method of claim 1 wherein: said bottom of said trench and said bottom of said first insulating layer have a separation distance of between about 4,000 Å and about 8,000 Å.
Claim 4
Dependent Claim
63 words
The method of claim 1 wherein: said first insulating layer is deposited to a thickness between about 5,000 Å and about 20,000 Å, the depth of said trench is between about 4,000 Å and 12,000 Å, and said bottom of said trench and said bottom of said first insulating layer having a separation distance of between about 4,000 Å and about 8,000 Å.
Claim 5
Independent Claim
230 words
The method of claim wherein: said first insulating layer comprises a material selected from the group consisting of silicon oxide and polyimide deposited to a thickness between about 5,000 Å and about 20,000 Å, the depth of said trench is between about 4,000 Å and 12,000 Å, said bottom of said trench and said bottom of said first insulating layer have a separation distance of between about 4,000 Å and about 8,000 Å, said first barrier layer comprises material selected from the group consisting of titanium nitride, tungsten nitride, titanium tungstide, and tantalum nitride, said second barrier layer comprises material selected from the group consisting of aluminum oxide, tantalum oxide and silicon nitride deposited layer by a method selected from chemical vapor deposition and physical vapor deposition, and said first barrier layer and said second barrier layer are deposited to a thickness between about 200 Å and about 2,000 Å, said copper layer is deposited by a method selected from chemical vapor deposition, physical vapor deposition, and electroplating, said copper layer is removed by a method selected from chemical-mechanical polishing and a blanket etch-back, said trench is etched by plasma dry etching, said via is etched by plasma dry etching, and said second insulating layer comprises a material selected from the group consisting of silicon oxide and polyimide deposited to a thickness between about 5,000 Å and about 20,000 Å.
Claim 6
Independent Claim
214 words
A method for manufacturing a copper connector in an integrated circuit comprising: (a) providing a silicon substrate, (b) depositing a first insulating layer on said silicon substrate to a predetermined thickness, said first insulating layer having a top surface and a bottom surface, (c) patterning and then etching to form a trench with an open top, walls on the sides, and a bottom of said trench in said first insulating layer extending to a depth less than said predetermined thickness, said bottom of said trench being above said bottom surface of said first insulating layer leaving a separation distance between said bottom of said trench and said bottom surface, (d) depositing a first barrier layer on said top surface of said first insulating layer and on all walls of said trench and said bottom of said trench, (e) depositing a copper layer on said first barrier layer so as to more than fill said trench, (f) removing said copper layer and said first barrier layer down to the level of said first insulating layer, thereby forming a damascene connector having an upper surface, (g) depositing a second barrier layer on said first insulating layer and said upper surface of said damascene connector, and (h) depositing a second insulating layer on said second barrier layer.
Claim 7
Independent Claim
214 words
A method for manufacturing a copper connector in an integrated circuit comprising: (a) providing a silicon substrate, (b) depositing a first insulating layer on said silicon substrate to a predetermined thickness, said first insulating layer having a top surface and a bottom surface, (c) patterning and then etching to form a trench with an open top, walls on the sides, and a bottom of said trench in said first insulating layer extending to a depth less than said predetermined thickness, said bottom of said trench being above said bottom surface of said first insulating layer leaving a separation distance between said bottom of said trench and said bottom surface, (d) depositing a first barrier layer on said top surface of said first insulating layer and on all walls of said trench and said bottom of said trench, (e) depositing a copper layer on said first barrier layer so as to more than fill said trench, (f) removing said copper layer and said first barrier layer down to the level of said first insulating layer, thereby forming a damascene connector having an upper surface, (g) depositing a second barrier layer on said first insulating layer and said upper surface of said damascene connector, and (h) depositing a second insulating layer on said second barrier layer.
Claim 8
Dependent Claim
38 words
The method of claim 5 comprising: (i) patterning and then etching said second insulating layer to form a via passing through said second insulating layer and said second barrier layer to said upper surface of said damascene connector.
Claim 9
Dependent Claim
14 words
The method of claim 6 wherein said via is etched by plasma dry etching.
Claim 10
Dependent Claim
23 words
The method of claim 5 wherein said first insulating layer comprises a material selected from the group consisting of silicon oxide and polyimide.
Claim 11
Dependent Claim
62 words
The method of claim 5 wherein: said first insulating layer is deposited to a thickness between about 5,000 Å and about 20,000 Å, said trench has a depth between about 4,000 Å and 12,000 Å, and said bottom of said trench and said bottom of said first insulating layer have a separation distance of between about 4,000 Å and about 8,000 Å.
Claim 12
Dependent Claim
45 words
The method of claim 5 wherein said first barrier layer comprises material selected from the group consisting of titanium nitride, tungsten nitride, titanium tungstide, and tantalum nitride and said first barrier layer is deposited to a thickness between about 200 Å and about 2,000 Å.
Claim 13
Dependent Claim
24 words
The method of claim 5 wherein said copper layer is deposited by a method selected from chemical vapor deposition, physical vapor deposition, and electroplating.
Claim 14
Dependent Claim
26 words
The method of claim 10 wherein said copper layer is removed down to the level of said first insulating layer by chemical-mechanical polishing, and blanket etch-back.
Claim 15
Dependent Claim
14 words
The method of claim 5 wherein said trench is etched by plasma dry etching.
Claim 16
Dependent Claim
67 words
The method of claim 5 wherein: said second insulating layer comprises a material selected from the group consisting of silicon oxide and polyimide, said second insulating layer is deposited to a thickness between about 5,000 Å and about 20,000 Å, and said bottom of said trench and said bottom of said first insulating layer have a separation distance of between about 4,000 Å and about 8,000 Å.
Claim 17
Dependent Claim
25 words
The method of claim 5 wherein said second barrier layer comprises material selected from the group consisting of aluminum oxide, tantalum oxide and silicon nitride.
Claim 18
Dependent Claim
22 words
The method of claim 15 wherein step (g) further comprises depositing the second barrier layer by chemical vapor deposition, physical vapor deposition.
Claim 19
Dependent Claim
35 words
The method of claim 5 wherein said first insulating layer comprises a material selected from the group consisting of silicon oxide and polyimide deposited to a thickness between about 5,000 Å and about 20,000 Å.
Claim 20
Dependent Claim
83 words
The method of claim 5 wherein: said first insulating layer comprises a material selected from the group consisting of a material selected from the group consisting of silicon oxide and polyimide deposited to a thickness between about 5,000 Å and about 20,000 Å, the depth of said trench is between about 4,000 Å and 12,000 Å, and said bottom of said trench and said bottom of said first insulating layer have a separation distance of between about 4,000 Å and about 8,000 Å.
Claim 21
Dependent Claim
115 words
The method of claim 5 wherein: said first insulating layer comprises a material selected from the group consisting of silicon oxide and polyimide deposited to a thickness between about 5,000 Å and about 20,000 Å, the depth of said trench is between about 4,000 Å and 12,000 Å, said bottom of said trench and said bottom of said first insulating layer have a separation distance of between about 4,000 Å and about 8,000 Å, said first barrier layer comprises material selected from the group consisting of titanium nitride, tungsten nitride, titanium tungstide, and tantalum nitride, and said second barrier layer comprises material selected from the group consisting of aluminum oxide, tantalum oxide and silicon nitride.
Claim 22
Dependent Claim
132 words
The method of claim 5 wherein: said first insulating layer comprises a material selected from the group consisting of silicon oxide and polyimide deposited to a thickness between about 5,000 Å and about 20,000 Å, the depth of said trench is between about 4,000 Å and 12,000 Å, said bottom of said trench and said bottom of said first insulating layer have a separation distance of between about 4,000 Å and about 8,000 Å, said first barrier layer comprises material selected from the group consisting of titanium nitride, tungsten nitride, titanium tungstide, and tantalum nitride, said second barrier layer comprises material selected from the group consisting of aluminum oxide, tantalum oxide and silicon nitride, and said first barrier layer is deposited to a thickness between about 200 Å and about 2,000 Å.
Claim 23
Dependent Claim
198 words
The method of claim 5 wherein: said first insulating layer comprises a material selected from the group consisting of silicon oxide and polyimide deposited to a thickness between about 5,000 Å and about 20,000 Å, the depth of said trench is between about 4,000 Å and 12,000 Å, said bottom of said trench and said bottom of said first insulating layer have a separation distance of between about 4,000 Å and about 8,000 Å, said first barrier layer comprises material selected from the group consisting of titanium nitride, tungsten nitride, titanium tungstide, and tantalum nitride, said first barrier layer is deposited to a thickness between about 200 Å and about 2,000 Å, said bottom of said trench and said bottom of said first insulating layer have a separation distance of between about 4,000 Å and about 8,000 Å, said second barrier layer comprises material selected from the group consisting of aluminum oxide, tantalum oxide and silicon nitride, said first barrier layer and said second barrier layer are deposited to a thickness between about 200 Å and about 2,000 Å, and said copper layer is deposited by a method selected from chemical vapor deposition, physical vapor deposition, and electroplating.
Claim 24
Dependent Claim
192 words
The method of claim 5 wherein: said first insulating layer comprises a material selected from the group consisting of silicon oxide and polyimide deposited to a thickness between about 5,000 Å and about 20,000 Å, the depth of said trench is between about 4,000 Å and 12,000 Å, said bottom of said trench and said bottom of said first insulating layer have a separation distance of between about 4,000 Å and about 8,000 Å, said first barrier layer comprises material selected from the group consisting of titanium nitride, tungsten nitride, titanium tungstide, and tantalum nitride, said first barrier layer is deposited to a thickness between about 200 Å and about 2,000 Å said second barrier layer comprises material selected from the group consisting of aluminum oxide, tantalum oxide and silicon nitride, said first barrier layer and said second barrier layer are deposited to a thickness between about 200 Å and about 2,000 Å, said copper layer is deposited by a method selected from chemical vapor deposition, physical vapor deposition, and electroplating, and said copper layer is removed down to the level of said first insulating layer by chemical-mechanical polishing, and blanket etch-back.
Claim 25
Dependent Claim
179 words
The method of claim 5 wherein: said first insulating layer comprises a material selected from the group consisting of silicon oxide and polyimide deposited to a thickness between about 5,000 Å and about 20,000 Å, the depth of said trench is between about 4,000 Å and 12,000 Å, said bottom of said trench and said bottom of said first insulating layer have a separation distance of between about 4,000 Å and about 8,000 Å, said first barrier layer comprises material selected from the group consisting of titanium nitride, tungsten nitride, titanium tungstide, and tantalum nitride, said second barrier layer comprises material selected from the group consisting of aluminum oxide, tantalum oxide and silicon nitride, said first barrier layer and said second barrier layer are deposited to a thickness between about 200 Å and about 2,000 Å, said copper layer is deposited by a method selected from chemical vapor deposition, physical vapor deposition, and electroplating, said copper layer is removed by a method selected from chemical-mechanical polishing and a blanket etch-back, and said trench is etched by plasma dry etching.
Claim 26
Dependent Claim
171 words
The method of claim 5 wherein: said first insulating layer comprises a material selected from the group consisting of silicon oxide and polyimide deposited to a thickness between about 5,000 Å and about 20,000 Å, the depth of said trench is between about 4,000 Å and 12,000 Å, said bottom of said trench and said bottom of said first insulating layer have a separation distance of between about 4,000 Å and about 8,000 Å, said first barrier layer comprises material selected from the group consisting of titanium nitride, tungsten nitride, titanium tungstide, and tantalum nitride, said second barrier layer comprises material selected from the group consisting of aluminum oxide, tantalum oxide and silicon nitride, said first barrier layer and said second barrier layer are deposited to a thickness between about 200 Å and about 2,000 Å, said copper layer is deposited by a method selected from chemical vapor deposition, physical vapor deposition, and electroplating, and said copper layer is removed by a method selected from chemical-mechanical polishing and a blanket etch-back.
Claim 27
Dependent Claim
213 words
The method of claim 5 wherein: said first insulating layer comprises a material selected from the group consisting of silicon oxide and polyimide deposited to a thickness between about 5,000 Å and about 20,000 Å, the depth of said trench is between about 4,000 Å and 12,000 Å, said bottom of said trench and said bottom of said first insulating layer have a separation distance of between about 4,000 Å and about 8,000 Å, said first barrier layer comprises material selected from the group consisting of titanium nitride, tungsten nitride, titanium tungstide, and tantalum nitride, said second barrier layer comprises material selected from the group consisting of aluminum oxide, tantalum oxide and silicon nitride, said first barrier layer and said second barrier layer are deposited to a thickness between about 200 Å and about 2,000 Å, said bottom of said trench and said bottom of said first insulating layer have a separation distance of between about 4,000 Å and about 8,000 Å, said copper layer is deposited by a method selected from chemical vapor deposition, physical vapor deposition, and electroplating, said copper layer is removed by a method selected from chemical-mechanical polishing and a blanket etch-back, said trench is etched by plasma dry etching, and said via is etched by plasma dry etching.
Claim 28
Dependent Claim
242 words
The method of claim 5 wherein: said first insulating layer comprises a material selected from the group consisting of silicon oxide and polyimide deposited to a thickness between about 5,000 Å and about 20,000 Å, the depth of said trench is between about 4,000 Å and 12,000 Å, said bottom of said trench and said bottom of said first insulating layer have a separation distance of between about 4,000 Å and about 8,000 Å, said first barrier layer comprises material selected from the group consisting of titanium nitride, tungsten nitride, titanium tungstide, and tantalum nitride, said second barrier layer comprises material selected from the group consisting of aluminum oxide, tantalum oxide and silicon nitride, said first barrier layer and said second barrier layer are deposited to a thickness between about 200 Å and about 2,000 Å, said bottom of said trench and said bottom of said first insulating layer have a separation distance of between about 4,000 Å and about 8,000 Å, said copper layer is deposited by a method selected from chemical vapor deposition, physical vapor deposition, and electroplating, said copper layer is removed by a method selected from chemical-mechanical polishing and a blanket etch-back, said trench is etched by plasma dry etching, said via is etched by plasma dry etching, and said second insulating layer comprises a material selected from the group consisting of silicon oxide and polyimide deposited to a thickness between about 5,000 Å and about 20,000 Å.
Claim 29
Dependent Claim
263 words
The method of claim 5 wherein: said first insulating layer comprises a material selected from the group consisting of silicon oxide and polyimide deposited to a thickness between about 5,000 Å and about 20,000 Å, the depth of said trench is between about 4,000 Å and 12,000 Å, said bottom of said trench and said bottom of said first insulating layer have a separation distance of between about 4,000 Å and about 8,000 Å, said first barrier layer comprises material selected from the group consisting of titanium nitride, tungsten nitride, titanium tungstide, and tantalum nitride, said second barrier layer comprises material selected from the group consisting of aluminum oxide, tantalum oxide and silicon nitride, said first barrier layer and said second barrier layer are deposited to a thickness between about 200 Å and about 2,000 Å, said bottom of said trench and said bottom of said first insulating layer have a separation distance of between about 4,000 Å and about 8,000 Å, said copper layer is deposited by a method selected from chemical vapor deposition, physical vapor deposition, and electroplating, said copper layer is removed by a method selected from chemical-mechanical polishing and a blanket etch-back, said trench is etched by plasma dry etching, said via is etched by plasma dry etching, said second insulating layer comprises a material selected from the group consisting of silicon oxide and polyimide deposited to a thickness between about 5,000 Å and about 20,000 Å, and step (g) further comprises depositing the second barrier layer by a method selected from chemical vapor deposition and physical vapor deposition.
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