US5976975A
Expired / Lapsed
US
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Refractory metal capped low resistivity metal conductor lines and vias
Assignee: GlobalFoundries Inc
•
Filing: 1998-07-10
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Granted: 1999-11-02
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Expires: 2018-07-10
Abstract
Abstract Capping a low resistivity metal conductor line or via with a refractory metal allows for effectively using chemical-mechanical polishing techniques because the-hard, reduced wear, properties of the refractory metal do not scratch, corrode, or smear during chemical-mechanical polishing. Superior conductive lines and vias are created using a combination of both physical vapor deposition (e.g., evaporation or collimated sputtering) of a low resistivity metal or alloy followed by chemical vapor deposition (CVD) of a refractory metal and subsequent planarization. Altering a ratio of SiH4 to WF6 during application of the refractory metal cap by CVD allows for controlled incorporation of silicon into the tungsten capping layer. Collimated sputtering allows for creating a refractory metal liner in an opening in a dielectric which is suitable as a diffusion barrier to copper based metalizations as well as CVD tungsten. Ideally, for faster diffusing metals like copper, liners are created by a two step collimated sputtering process wherein a first layer is deposited under relatively low vacuum pressure where directional deposition dominates (e.g., below lmtorr) and a second layer is deposited under relatively high vacuum pressure where scattering deposition dominates (e.g., above 1 mTorr). For refractory metals like CVD tungsten, the liner can be created in one step using collimated sputtering at higher vacuum pressures.
Inventors
- 👤 Rajiv V. Joshi
- 👤 Jerome J. Cuomo
- 👤 Hormazdyar M. Dalal
- 👤 Louis L. Hsu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 04:26
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/032; H10W20/033; H10P; H10P14/00; H10P14/40; H10P14/42; H10P14/43; H10P14/44; H10W20/036; H10W20/037; H10W20/038; H10W20/039; H10W20/056; H10W20/062; H10W20/40; H10W20/41; H10W20/425; H10W20/44; H10W20/4403; H10W20/4421; H10W20/4424; H10W70/00; H10W70/60; H10W70/62; H10W70/66; Y; Y10; Y10S; Y10S148/00; Y10S148/015; Y10S257/00; Y10S257/915; Y10S438/00; Y10S438/959
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
55 words
A method of creating a liner in high aspect ratio, submicron holes and lines comprising the step of sputtering a refractory metal or an alloy or compound thereof through a collimator into a high aspect ratio, submicron hole or line at a pressure where scattering deposition dominates to create a liner effective to inhibit diffusion.
Claim 2
Independent Claim
55 words
A method of creating a liner in high aspect ratio, submicron holes and lines comprising the step of sputtering a refractory metal or an alloy or compound thereof through a collimator into a high aspect ratio, submicron hole or line at a pressure where scattering deposition dominates to create a liner effective to inhibit diffusion.
Claim 3
Dependent Claim
13 words
The method of claim 1 wherein the liner is a substantially conformal coating.
Claim 4
Dependent Claim
19 words
The method of claim 1 wherein the aspect ratio of said hole or line is greater than about 2:1.
Claim 5
Dependent Claim
17 words
The method of claim 1 wherein the collimator has an aspect ratio of greater than about 1:1.
Claim 6
Dependent Claim
14 words
The method of claim 1 wherein the pressure is greater than about 1 mTorr.
Claim 7
Dependent Claim
19 words
The method of claim 1 further comprising the step of introducing a metal or metal alloy within the liner.
Claim 8
Dependent Claim
19 words
The method of claim 1 further comprising the step of introducing copper or a copper-containing alloy within the liner.
Claim 9
Dependent Claim
94 words
The method of claim 1 wherein the sputtering step comprises a first step of sputtering a first refractory metal or an alloy or compound thereof through a first collimator into the high aspect ratio, submicron hole or line at a pressure where scattering deposition dominates and a second step of sputtering a second refractory metal or an alloy or compound thereof through a second collimator into the high aspect ratio, submicron hole or line at a pressure where scattering deposition dominates, the first and second sputtering steps creating the liner effective to inhibit diffusion.
Claim 10
Dependent Claim
19 words
The method of claim 8 wherein the first and second refractory metals or alloys or compounds thereof are different.
Claim 11
Independent Claim
51 words
A method of creating a liner in high aspect ratio, submicron holes and lines comprising the step of sputtering a metal or an alloy or compound thereof into a high aspect ratio, submicron hole or line pressure where directional deposition dominates, without collimation, to create a liner effective to inhibit diffusion.
Claim 12
Independent Claim
51 words
A method of creating a liner in high aspect ratio, submicron holes and lines comprising the step of sputtering a metal or an alloy or compound thereof into a high aspect ratio, submicron hole or line pressure where directional deposition dominates, without collimation, to create a liner effective to inhibit diffusion.
Claim 13
Dependent Claim
13 words
The method of claim 10 wherein the liner is a substantially conformal coating.
Claim 14
Dependent Claim
19 words
The method of claim 10 wherein the aspect ratio of said hole or line is greater than about 2:1.
Claim 15
Dependent Claim
17 words
The method of claim 10 wherein said pressure where direction deposition dominates is below about 1 mTorr.
Claim 16
Dependent Claim
23 words
The method of claim 10 wherein metal or an alloy or compound thereof is a refractory metal or an alloy or compound thereof.
Claim 17
Dependent Claim
19 words
The method of claim 10 further comprising the step of introducing a metal or metal alloy within the liner.
Claim 18
Dependent Claim
19 words
The method of claim 10 further comprising the step of introducing copper or a copper-containing alloy within the liner.
Claim 19
Dependent Claim
92 words
The method of claim 10 wherein the sputtering step comprises a first step of sputtering a first metal or an alloy or compound thereof through a first collimator into the high aspect ratio, submicron hole or line at a pressure where scattering deposition dominates and a second step of sputtering a second metal or an alloy or compound thereof through a second collimator into the high aspect ratio, submicron hole or line at a pressure where scattering deposition dominates, the first and second sputtering steps creating the liner effective to inhibit diffusion.
Claim 20
Dependent Claim
18 words
The method of claim 17 wherein the first and second metals or alloys or compounds thereof are different.
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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) | 2002-11-01 | 2003-05-03 | 2003-11-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-11-01 | 2007-05-03 | 2007-11-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-11-01 | 2011-05-03 | 2011-11-02 | $7700.00 | Window Closed / Lapsed |