EP0558004A2
Expired / Lapsed
EP
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Refractory metal capped low resistivity metal conductor lines and vias
Assignee: Siemens AG
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Filing: 1993-02-25
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Granted: —
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Expires: 2013-02-25
Abstract
Abstract Electrically conducting vias and lines are created by a three step process. First, a controlled amount of a soft, low resistivity metal (12) is deposited in a trench or hole to a point below the top surface of the dielectric (10) in which the trench or hole is formed. Subsequently, the low resistivity metal (12) is overcoated with a hard metal (16) such as CVD tungsten. Finally, chemical-mechanical polishing is used to planarize the structure. An ideal method for partially filling trenches or holes in a substrate is by sputtering at elevated temperatures such that metallization at the bottom of a trench or hole separates from metallization on a top surface adjacent the trench or hole. An etchback procedure may also be used to separate metallization in a trench or hole from metallization adjacent a trench or hole. Trenchs and holes may also be filled by selective deposition. In addition, trenches and holes may also be lined by a metal liner (18) prior to metallization (12) deposition which can serve as a diffusion barrier.
Inventors
- 👤 William Joseph Cote
- 👤 Pei-Ing Paul Lee
- 👤 Thomas Edwin Sandwick
- 👤 Bernd Michael Vollmer
- 👤 Victor Vynorius
- 👤 Stuart Howard Wolff
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 11:53
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/032; H10W20/042; H10W20/045; H10W20/033; H10W20/037; H10W20/056; H10W20/40; H10W20/41; H10W20/42; H10W20/425
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
139 words
A method for producing capped damascene lines or vias on a substrate, comprising the steps of: depositing a soft metal or metal alloy having low resistance in a trench or hole in a substrate at a temperature sufficient to allow separation of said soft metal or metal alloy into a first portion deposited in said trench or hole and a second portion deposited on a surface of said substrate, said first portion being positioned below said surface of said substrate; depositing a hard metal or metal alloy over said soft metal or metal alloy; and polishing said substrate to planarize a line or a via created in said trench or said hole, respectively, with said surface of said substrate, whereby said hard metal or metal alloy protects said soft metal or metal alloy from scratching and corrosion during polishing.
Claim 2
Dependent Claim
22 words
A method as recited in claim 1 wherein said step of depositing said soft metal or metal alloy is achieved by sputtering.
Claim 3
Dependent Claim
13 words
A method as recited in claim 2 wherein said sputtering accompanied by collimation.
Claim 4
Dependent Claim
20 words
A method as recited in claim 2 wherein said temperature used in said step of depositing is greater than 100°C.
Claim 5
Dependent Claim
42 words
A method as recited in claim 1 further comprising the step of lining said trench or hole with a material which enhances a surface mobility of said soft metal or alloy deposited in said step of depositing said soft metal or alloy.
Claim 6
Dependent Claim
20 words
A method as recited in claim 1 wherein said temperature used in said step of depositing is greater than 100°C.
Claim 7
Dependent Claim
39 words
A method as recited in claim 1 wherein said temperature used in said step of depositing is chosen to substantially flatten a top surface of said first portion of said soft metal or alloy in said trench or hole.
Claim 8
Dependent Claim
24 words
A method as recited in claim 1 wherein said step of depositing said hard metal or metal alloy is performed by chemical vapor deposition.
Claim 9
Dependent Claim
23 words
A method as recited in claim 1 wherein said step of polishing is performed with an acid based chemical-mechanical polishing compound containing alumina.
Claim 10
Dependent Claim
43 words
A method as recited in claim 1 further comprising the step of lining said trench or hole with a material which acts as a diffusion barrier to said soft metal or alloy deposited in said step of depositing said soft metal or alloy.
Claim 11
Independent Claim
157 words
A method for producing capped damascene lines or vias on a substrate, comprising the steps of: depositing a soft metal or metal alloy having low resistance over a substrate having at least one a trench or hole, said step of depositing filling said trench or hole to a point below a top surface of said substrate; removing any soft metal or metal alloy which connects a first portion of said soft metal or metal alloy in said trench or hole with a second portion of said soft metal or metal alloy on said top surface of said substrate; depositing a hard metal or metal alloy over said soft metal or metal alloy; and polishing said substrate to planarize a line or a via created in said trench or said hole, respectively, with said surface of said substrate, whereby said hard metal or metal alloy protects said soft metal or metal alloy from scratching and corrosion during polishing.
Claim 12
Dependent Claim
17 words
A method as recited in claim 11 wherein said step of removing is achieved by sputter etching.
Claim 13
Independent Claim
124 words
A method for producing capped damascene lines or vias on a substrate, comprising the steps of: depositing a metal seed layer in a trench or hole in a substrate; selectively depositing a soft metal or metal alloy having low resistance on said metal seed layer, said step of selectively depositing filling said trench or hole to a point below a top surface of said substrate; depositing a hard metal or metal alloy over said soft metal or metal alloy; and polishing said substrate to planarize a line or a via created in said trench or said hole, respectively, with said surface of said substrate, whereby said hard metal or metal alloy protects said soft metal or metal alloy from scratching and corrosion during polishing.
Claim 14
Dependent Claim
23 words
A method as recited in claim 13 wherein said step of selectively depositing said soft metal or metal alloy is performed by growing.
References Cited (Backward Citations)
No citation records indexed.
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