US5942799A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multilayer diffusion barriers
Assignee: Novellus Systems Inc
•
Filing: 1997-11-20
•
Granted: 1999-08-24
•
Expires: 2017-11-20
Abstract
Abstract Multilayer diffusion barriers are used in integrated circuits. These diffusion barriers provide high electrical conductivity to carry current efficiently with fast response time, and additionally suppress diffusion between interconnect conductors, e.g. Cu, and the semiconductor device. Moreover, the present multilayer diffusion barriers adhere well to the underlying materials as well as to Cu. In a preferred embodiment, the diffusion barriers comprise bilayers, each containing a first sublayer formed of a refractory metal, or a refractory metal nitride; and a second sublayer formed of a refractory metal nitride, a refractory metal silicon nitride, a refractory metal silicon boride, or a refractory metal oxonitride. Multilayer diffusion barriers are deposited easily by CVD in a multistation module. The present structures can be applied to sub-0.25 μm logic, memory and application specific circuits with Cu as the primary conductor.
Inventors
- 👤 Michal Danek
- 👤 Karl B. Levy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:44
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/40; H10W20/41; H10W20/425
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
107 words
A semiconductor device comprising: an underlying device region; an overlying interconnect region; and a multilayer diffusion barrier providing an electrically conductive path between said device region and said interconnect region, said multilayer diffusion barrier comprising at least two sublayers comprising a first sublayer consisting of a first material and a second sublayer adjacent said first sublayer consisting of a second material different from said first material, said multilayer diffusion barrier suppressing diffusion of atoms between said device region and said interconnect region, said at least two sublayers comprising at least two bilayers, each of said bilayers consisting of two of said sublayers having respectively chemically distinct compositions.
Claim 2
Dependent Claim
107 words
A semiconductor device comprising: an underlying device region; an overlying interconnect region; and a multilayer diffusion barrier providing an electrically conductive path between said device region and said interconnect region, said multilayer diffusion barrier comprising at least two sublayers comprising a first sublayer consisting of a first material and a second sublayer adjacent said first sublayer consisting of a second material different from said first material, said multilayer diffusion barrier suppressing diffusion of atoms between said device region and said interconnect region, said at least two sublayers comprising at least two bilayers, each of said bilayers consisting of two of said sublayers having respectively chemically distinct compositions.
Claim 3
Dependent Claim
22 words
The device according to claim 1, wherein said interconnect region contains a material selected from the group consisting of aluminum and copper.
Claim 4
Dependent Claim
29 words
The device according to claim 1, wherein at least one of said sublayers consists of a material exhibiting electrical resistivity of the order of less than 50 microohm cm.
Claim 5
Dependent Claim
23 words
The device according to claim 1, wherein at least one of said sublayers consists of a material exhibiting adhesion to said interconnect region.
Claim 6
Dependent Claim
23 words
The device according to claim 1, wherein at least one of said sublayers consists of a material exhibiting adhesion to said device region.
Claim 7
Dependent Claim
47 words
The device according to claim 1, wherein at least one of said sublayers consists of a material exhibiting greater suppression of diffusion of atoms between the materials of said interconnect region and said device region, respectively, than does the material of a second one of said sublayers.
Claim 8
Dependent Claim
17 words
The device according to claim 1, wherein said first sublayer provides nucleation for forming said second sublayer.
Claim 9
Dependent Claim
27 words
The device according to claim 1, wherein said second material is not chemically reactive with said first material under conditions encountered during the fabrication of said device.
Claim 10
Dependent Claim
28 words
The device according to claim 1, wherein at least one of said sublayers contains a material that provides a wetting surface for a material of said interconnect region.
Claim 11
Dependent Claim
37 words
The device according to claim 1, wherein a first one of said sublayers and a second one of said sublayers generate compressive and tensile mechanical stresses respectively, thereby providing mechanical stress compensation in said multilayer diffusion barrier.
Claim 12
Dependent Claim
93 words
A semiconductor device comprising: an underlying device region; an overlying interconnect region; and a multilayer diffusion barrier providing an electrically conductive path between said device region and said interconnect region, said multilayer diffusion barrier comprising at least two sublayers comprising a first sublayer consisting of a first material and a second sublayer adjacent said first sublayer consisting of a second material different from said first material, said multilayer diffusion barrier suppressing diffusion of atoms between said device region and said interconnect region, wherein said first sublayer provides nucleation for forming said second sublayer.
Claim 13
Dependent Claim
93 words
A semiconductor device comprising: an underlying device region; an overlying interconnect region; and a multilayer diffusion barrier providing an electrically conductive path between said device region and said interconnect region, said multilayer diffusion barrier comprising at least two sublayers comprising a first sublayer consisting of a first material and a second sublayer adjacent said first sublayer consisting of a second material different from said first material, said multilayer diffusion barrier suppressing diffusion of atoms between said device region and said interconnect region, wherein said first sublayer provides nucleation for forming said second sublayer.
Claim 14
Dependent Claim
22 words
The device according to claim 11, wherein said interconnect region contains a material selected from the group consisting of aluminum and copper.
Claim 15
Dependent Claim
27 words
The device according to claim 11, wherein one of said sublayers consists of a material exhibiting electrical resistivity of the order of less than 50 microohm cm.
Claim 16
Dependent Claim
23 words
The device according to claim 11, wherein at least one of said sublayers consists of a material exhibiting adhesion to said interconnect region.
Claim 17
Dependent Claim
23 words
The device according to claim 11, wherein at least one of said sublayers consists of a material exhibiting adhesion to said device region.
Claim 18
Dependent Claim
30 words
The device according to claim 11, wherein said first material exhibits suppression of diffusion of atoms between said interconnect region and said device region greater than does said second material.
Claim 19
Dependent Claim
27 words
The device according to claim 11, wherein said second material is not chemically reactive with said first material under conditions encountered during the fabrication of said device.
Claim 20
Dependent Claim
28 words
The device according to claim 11, wherein at least one of said sublayers contains a material that provides a wetting surface for a material of said interconnect region.
Claim 21
Dependent Claim
31 words
The device according to claim 11, wherein said first material and said second material generate compressive and tensile mechanical stresses respectively, thereby providing mechanical stress compensation in said multilayer diffusion barrier.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-08-23 | 2003-02-22 | 2003-08-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-08-23 | 2007-02-22 | 2007-08-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-08-23 | 2011-02-22 | 2011-08-24 | $7700.00 | Window Closed / Lapsed |