US5913147A
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Method for fabricating copper-aluminum metallization
Assignee: GlobalFoundries Inc
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Filing: 1997-01-21
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Granted: 1999-06-15
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Expires: 2017-01-21
Abstract
Abstract A method for fabricating copper-aluminum metallization utilizing the technique of electroless copper deposition is described. The method provides a self-encapsulated copper-aluminum metallization structure.
Inventors
- 👤 Valery Dubin
- 👤 Chiu Ting
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:10
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/40; H10W20/41; H10W20/44; H10W20/4403; H10W20/4421; H10W20/4424; H10P; H10P14/00; H10P14/40; H10P14/46; H10W20/01; H10W20/031; H10W20/056; H10W20/425
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
86 words
A method for fabricating copper alloy metallization in a recess defined in a dielectric layer of a substrate, the method comprising the steps of: depositing a diffusion barrier layer on the surfaces of the recess; depositing a copper alloy layer on the diffusion barrier layer; and annealing the copper alloy layer to form a first thin oxide layer on an exposed surface of the copper alloy layer, and a second thin oxide layer at the interface between the copper alloy layer and the diffusion barrier layer.
Claim 2
Independent Claim
86 words
A method for fabricating copper alloy metallization in a recess defined in a dielectric layer of a substrate, the method comprising the steps of: depositing a diffusion barrier layer on the surfaces of the recess; depositing a copper alloy layer on the diffusion barrier layer; and annealing the copper alloy layer to form a first thin oxide layer on an exposed surface of the copper alloy layer, and a second thin oxide layer at the interface between the copper alloy layer and the diffusion barrier layer.
Claim 3
Dependent Claim
40 words
A method as in claim 1, wherein the diffusion barrier layer comprises a metal composite selected from the group of tantalum, tantalum nitride, tungsten, tungsten nitride, titanium tungsten, titanium nitride, tantalum silicon nitride, titanium silicon nitride, or tungsten silicon nitride.
Claim 4
Dependent Claim
13 words
A method as in claim 1, wherein the copper alloy layer comprises aluminum.
Claim 5
Dependent Claim
41 words
A method as in claim 3, wherein the first thin layer of oxide comprises an aluminum oxide (Al 2 O 3 ), and the second thin layer of oxide comprises an aluminum oxide and copper-aluminum alloy (Al 2 O 3 +CuAl).
Claim 6
Dependent Claim
30 words
A method as in claim 3, wherein the depositing step comprises: depositing a copper-aluminum alloy film on the diffusion barrier layer; and depositing electroless copper on the copper-aluminum alloy film.
Claim 7
Dependent Claim
56 words
A method as in claim 5, wherein said step of depositing electroless copper is performed in a solution, having a pH of 11.5-13.5, containing: a) 5-10 g/l CuSO 4 .5H 2 O; b) 5-10 g/l glyoxylic acid, or 5-10 ml/l formaldehyde; c) 10-35 g/l KOH; and d) 0.01-10 g.l RE 610, or 0.01-1 g/l polyethylene glycol.
Claim 8
Dependent Claim
24 words
A method as in claim 5, wherein the depositing step further comprises the step of: filling the recess using the technique of copper electroplating.
Claim 9
Dependent Claim
41 words
A method as in claim 7, wherein said step of copper electroplating is performed using a 0.1-100 millisecond envelope of cathodic pulses, having a 50-90% duty cycle, followed by a 0.1-10 millisecond envelope of anodic pulses, having a 50-90% duty cycle.
Claim 10
Dependent Claim
12 words
A method as in claim 1, wherein the dielectric comprises silicon dioxide.
Claim 11
Dependent Claim
24 words
A method as in claim 1, wherein said copper alloy layer is formed by first depositing a CuAl bilayer, followed by an annealing step.
Claim 12
Dependent Claim
26 words
A method as in claim 10, wherein said annealing step of said CuAl bilayer is carried out at a temperature between 150° C. to 500° C.
Claim 13
Independent Claim
89 words
A method for fabricating copper alloy metallization in a recess defined in a dielectric layer of a substrate, the method comprising the steps of: depositing a U-shaped diffusion barrier layer on the surfaces of the recess; depositing a copper alloy layer on the U-shaped diffusion barrier layer; and annealing the copper alloy layer to form a first thin oxide layer on an exposed surface of the copper alloy layer, and a second thin oxide layer at the interface between the copper alloy layer and the U-shaped diffusion barrier layer.
Claim 14
Independent Claim
89 words
A method for fabricating copper alloy metallization in a recess defined in a dielectric layer of a substrate, the method comprising the steps of: depositing a U-shaped diffusion barrier layer on the surfaces of the recess; depositing a copper alloy layer on the U-shaped diffusion barrier layer; and annealing the copper alloy layer to form a first thin oxide layer on an exposed surface of the copper alloy layer, and a second thin oxide layer at the interface between the copper alloy layer and the U-shaped diffusion barrier layer.
Claim 15
Dependent Claim
31 words
A method as in claim 12, wherein the depositing step comprises: depositing a copper-aluminum alloy film on the U-shaped diffusion barrier layer; and depositing electroless copper on the copper-aluminum alloy film.
References Cited (Backward Citations)
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-06-14 | 2002-12-14 | 2003-06-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-06-14 | 2006-12-14 | 2007-06-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-06-14 | 2010-12-14 | 2011-06-15 | $7700.00 | Window Closed / Lapsed |